From Wikiversity
Jump to navigation Jump to search
This is a photograph of the skeleton of Alligator prenasalis. Credit: Ghedoghedo.{{free media}}

Def. the study "of the forms of life existing in prehistoric or geologic times"[1] is called paleontology.

Clades from the paleontological rock record sometimes display a clade asymmetry. "(Our two cases of Metazoa and mammals represent the first filling of life's ecological "barrel" for multicellular animals, and the radiation of mammals into roles formerly occupied by dinosaurs.)"[2]

Fossils[edit | edit source]

This may be an ammonite fossil. Credit: Halvard : from Norway. {{free media}}
Examples are index fossils. Credit: United States Geological Survey.{{free media}}

Def. "the mineralized remains of an animal or plant"[3] or any "preserved evidence of ancient life, including shells, imprints, burrows, coprolites, and organically-produced chemicals"[4] is called a fossil.

Derived terms include "ichnofossil, index fossil, living fossil, "mesofossil, microfossil,"[5] and trace fossil".[6]

Def. "any ancient remains of a plant or animal that lived during a specific geological period and that can be used to date the containing rocks"[7] is called an index fossil.

Fossil Scientific Name Geological time interval Million Years Ago
Calico scallop 02.jpg
Argopecten gibbus Calico scallop

Atlantic calico scallop Argopecten gibbus
Quaternary 1.8 Ma
Neptunea, Neptunea tabulata Quaternary 1.8 Ma
Viviparus glacialis - Rosmalen - Late Tiglian.jpg Viviparus glacialis Tiglian (Early Pleistocene) 2.3-1.8 Ma
Calyptraphorus velatus Tertiary
Venericardia, Venericardia planicosta Eocene
Scaphites hippocrepis Cretaceous Cretaceous, period end Cretaceous
Inoceramus labiatus Cretaceous
Ammonit - Wüstenhaus.jpg
Perisphinctes tiziani Jurassic 201.3 to 145 million years ago
Nerinea, Nerinea trinodosa Jurassic
Tropites subbullatus Triassic
Monotis fossil shells - Kiritehere beach.jpg Monotis subcircularis Triassic
Leptodus americanus Permian
Parafusulina Parafusulina bosei Permian
Dictyoclostus americanus Pennsylvanian
Lophophyllidium proliferum Pennsylvanian
Cactocrinus multibrachiatus Mississippian
Prolecanites gurleyi Mississippian
Mucrospirifer mucronatus Silica Shale.JPG
Mucrospirifer mucronatus Devonian 416-359 Ma
Palmatolepis unicornis Devonian
Tetragraptus, Tetragraptus fructicosus Ordovician
BLW Trilobite (Paradoxides sp.).jpg Paradoxides Cambrian 509-500 Ma
Billingselia corrugata Cambrian
Archeocyathids.JPG Archaeocyatha, Archaocyathids Cambrian 529-509 Ma

Geologic time[edit | edit source]

This clock representation shows some of the major units of geological time and definitive events of Earth history. Credit: Woudloper.

At right is a geologic clock representation which shows some of the major units of geological time and definitive events of Earth history, where the Hadean eon represents the time before fossil record of life on Earth; its upper boundary is now regarded as 4.0 Ga (billion years ago).[8]

Quaternary[edit | edit source]

Meghalayan[edit | edit source]

19th Century[edit | edit source]

Charred material from the Lake Pátzcuaro Basin, Mexico, was radiocarbon dated at 1715-1895 AD (120 b2k intercept).[9]

18th Century[edit | edit source]

The more recent dated logboat of Ireland is from or known as Bond's Bridge, Cos AmlaghJTyrone, to 245 ± 15 b2k.[10]

17th Century[edit | edit source]

A logboat from Northern Ireland designated GrN-14744 dates to 305 ± 30 b2k.[10]

16th Century[edit | edit source]

A logboat from Ireland (Derryloughan B, Co. Tyrone) designated GrN-14738 dates to 410 ± 35 b2k.[10]

15th century[edit | edit source]

A logboat from Ireland, Derryloughan A, Co. Tyrone, designated GrN-14737, has been radiocarbon dated to 570 ± 25 BP or b2k.[10]

14th century[edit | edit source]

Radiocarbon dating of a corner piece of the Shroud of Turin placed it between the years 1260 and 1390,[11] in the High to Late Middle Ages, which is consistent with "its first recorded exhibition in France in 1357."[12]

Charred materials from the Lake Pátzcuaro Basin, Mexico, were radiocarbon dated at 1170-1300 AD (680 b2k intercept), 1230-1315 AD (665 b2k intercept), 1300-1415 AD (605 b2k intercept), 1320-1535 AD (540 b2k intercept) and 1320-1435 AD (500 b2k intercept).[9]

13th century[edit | edit source]

The book was bound more than 100 years later with covers made of oak surrounded by leather, where the oak has been dated to 1264 using dendrochronology, and the oak trees used grew in the vicinity of Skara.[13]

"In a meta-analysis of 1,434 radiocarbon dates from the region, reliable short-lived samples reveal that the colonization of East Polynesia occurred in two distinct phases: earliest in the Society Islands A.D. ~1025–1120, four centuries later than previously assumed; then after 70–265 y, dispersal continued in one major pulse to all remaining islands [15 archipelagos of East Polynesia, including New Zealand, Hawaii, and Rapa Nui] A.D. ∼1190–1290."[14]

12th century[edit | edit source]

Recent dating of Sweden's oldest book, the Skara Missal [in the image on the left] shows that the book is just that: Sweden's oldest.[13]

Researchers at Lund University concluded using radiocarbon dating that the book's pages are from the year 1150, i.e. at the time of the opening of the Skara cathedral.[13]

Charred materials from the Lake Pátzcuaro Basin, Mexico, were radiocarbon dated at 970-1,170 AD (885 b2k intercept) and 1,010-1275 AD (775 b2k intercept).[9]

11th century[edit | edit source]

These are five Överhogdal tapestries found 1909 in Överhogdal, Sweden. Credit: unknown.{{free media}}
Skuldelev II is a warship built in the Norse–Gaelic community of Dublin (c. 1042). Credit: Casiopeia.

"All 5 pieces of the famous Swedish Överhogdal [tapestries such as the portion shown in the image on the right] were examined [by radiocarbon dating to 900 - 1100]."[15]

Radiocarbon dating of charcoal fragments from Koumbi Salehin, a settlement in south east Mauritania, indicate the site was continuously occupied from the 8th/9th to the 13th centuries.[16]

Classical period[edit | edit source]

10th century[edit | edit source]

The Norse settlement of Vinland at L’Anse aux Meadows National Historic Site, Newfoundland, in the image on the left, has been radiocarbon dated to c. 1000, or 1,000 b2k.

8th century[edit | edit source]

Pile from The Strood, in Roman cut (223 cm high), re-dated from the late 1st c. AD to the 7th/8th c. AD. Roman lead covered box with Roman glass urn (100-120 CE) from Mersea’s Roman barrow. Credit: Gunnar Heinsohn.{{fairuse}}

"The Strood causeway to Mersea Island was thought to be Roman, built in the 1st c. AD. It leads to Mersea’s Roman burial mound (barrow) where a typical Roman lead covered box with a no less typical Roman glass urn (tentatively dated between 100 and 120 AD) was retrieved [in the image on the right]. Oak piles in typical Roman cut were discovered in 1978. Up to the 1980s it was never doubted that the dam was built by Romans in the 1st c. AD to reach their settlements on the Island."[17]

"Scientific dating methods have been applied to some substantial oak piles discovered beneath the Strood in 1978, when a water-main was being laid. They indicate that the structure was probably built between A.D. 684 and 702. The piles were discovered at the south end of the causeway where the trench was at its deepest—they were about 1.6m below the present ground level and were sealed by a series of road surfaces. Seven piles were recovered and samples were submitted to Harwell laboratory for radiocarbon dating to get a rough idea of the date. Samples from four of the piles were sent to the University of Sheffield for tree ring dating (dendrochronology). The remaining three piles are now in the Colchester and Essex Museum. The dating of the construction to AD 684 to 702 was regarded as conclusive."[18]

Subatlantic period[edit | edit source]

"The main discontinuity in the climatic condition during the Bronze Age and Iron Age transition can be identified in the boundary from Subatlantic to Subboreal (2800-2500 BP; 996/914-766/551 2σ cal. BC). Such period “has globally been identified as a time of marked climatic change. Stratigraphical, paleobotanical and archaeological evidence point to a change from a dry and warm to a more humid and cool climate in central and northwestern Europe” (Tinner et al. 2003). The climatic deterioration which characterizes this chronological range is directly responsible of the plateau in the calibration curve between 760 and 420 BC (2500-2425 BP) (see chapter The climatic oscillation around 2700 BP (896/813 2σ cal. BC) has been detected worldwide. Van Geel et al. (1996, 1998) and Speranza et al. (2002) found an abrupt shift around 850 BC in changing species composition of peat-forming mosses in European Holocene raised bog deposits. The change was from mosses preferring warm conditions to those preferring colder and wetter environments. Archaeological evidence supports such a change. Bronze Age settlements located in the Netherlands were suddenly abandoned after a long period of occupation which last around one millennium (Dergachev et al. 2004). Other studies confirmed the climatic discontinuity; Schilman et al. (2001) studied δ18O and δ13C in deposits from the southeastern Mediterranean, off Israel, and recognized the presence of two humid events in the time ranges of 3500-3000 BP (1884/1772-1263/1215 2σ cal. BC) and 1700-1000 BP (332/389-1016/1030 2σ cal. AD) and a period of arid conditions between 3000 and 1700 BP (1263/1215 2σ cal. BC- 332/389 2σ cal. AD). Barber and Langdon (2001) identified three main long climatic deteriorations 2900-2830 BP (1119/1037-1012/934 2σ cal. BC), 2630-2590 BP (810/797-801/788 2σ cal. BC) and 1550-1400 BP (430/549-637/658 2σ cal. AD) through the analysis of plant macrofossils in a peat deposit of Walton Moss located in Northern England and comparing such data with a temperature reconstruction based on chironomids in the sediment of a nearby lake."[19]

Subboreal period[edit | edit source]

The "period around 850-760 BC, [2850-2760 b2k, is] characterised by a decrease in solar activity and a sharp increase of Δ 14C [...] the local vegetation succession, in relation to the changes in atmospheric radiocarbon content, shows additional evidence for solar forcing of climate change at the Subboreal - Subatlantic transition."[20]

The "apparent reality of social equality testified by LBA urnfield burials can be definitely discarded at the Iron Age transition by the archaeological excavation at the Hexenbergle site, near Wehringen in Bayern (Germany). The monumental radiocarbon dated mound with a cremation burial of an adult male accompanied by a great amount of objects, including a sword, elements decorating a wagon and an extensive set of painted pottery (Hennig 1995). The dendrochronological date obtained on the wagon (778±5BC) provides a precise temporal location for an upper-class deceased with sepulchral paraphernalia in the Hallstatt period (Friedrich & Henning 1995, 1996)."[19]

Bronze Ages[edit | edit source]

Radiocarbon "data indicate that the New Kingdom of Egypt started between 1570 and 1544 B.C.E [3570 - 3544 b2k]."[21]

High precision radiocarbon dating of 18 samples from Jericho, including six samples of carbonized cereal from the burnt stratum, gave the age of the strata as 1562 BC, with a margin of error of 38 years [3562 ± 38 b2k].[22]

A logboat from Ireland (Inch Abbey, Co. Down) was dendrochronology dated to 4140 b2k.[10]

A logboat made from alder from Denmark (Verup l) designated K-4098B was radiocarbon dated to 4220 ± 75 b2k.[10]

A logboat from Ireland (Ballygowan, Co. AmJagh) designated GrN-20550 was radiocarbon dated to 4660 ± 40 b2k.[10]

Atlantic[edit | edit source]

Two skeletons of women aged between 25 and 35 years, dated between 6740 and 5680 BP, both of whom died a violent death. Found at Téviec, France, in 1938. Credit: Didier Descouens.{{free media}}

The "Atlantic period [is from] 4.6–6 ka [6,000 to 4,600 b2k]."[23]

"The Atlantic is equivalent to Pollen Zone VII."[24]

Northgrippian[edit | edit source]

The "Scandinavian one 2000 years earlier [8,000 b2k]."[25]

Boreal transition[edit | edit source]

"In recent years, the German oak chronology has been extended to 7938 BC [9938 b2k]. For earlier intervals, tree-ring chronologies must be based on pine, because oak re-emigrated to central Europe at the Preboreal/Boreal transition, at about 8000 BC [10,000 b2k]."[26]

"The age range, 7145-7875 BC [9145-9875 b2k], is represented by the oak chronology, 'Main9'."[26]

"The age range, 7833-9439 BC [9833-11439 b2k], is covered by the 1784-yr pine chronology."[26]

Pre-Boreal transition[edit | edit source]

This is an image of Aepyornis maximus tibiotarsus Credit: V. R. Pérez.{{fairuse}}

"About 9000 years ago the temperature in Greenland culminated at 4°C warmer than today. Since then it has become slowly cooler with only one dramatic change of climate. This happened 8250 years ago [...]. In an otherwise warm period the temperature fell 7°C within a decade, and it took 300 years to re-establish the warm climate. This event has also been demonstrated in European wooden ring series and in European bogs."[25]

"The Pre-boreal period marks the transition from the cold climate of the Late-glacial to the warmer climate of Post-glacial time. This change is immediately obvious in the field from the nature of the sediments, changing as they do from clays to organic lake muds, showing that at this time a more or less continuous vegetation cover was developing."[27]

"At the beginning of the Pre-boreal the pollen curves of the herbaceous species have high values, and most of the genera associated with the Late-glacial fiora are still present e.g. Artemisia, Polemomium and Thalictrum. These plants become less abundant throughout the Pre-boreal, and before the beginning of the Boreal their curves have reached low values."[27]

">10,500-year-old human-modified bones for the extinct elephant birds Aepyornis and Mullerornis, [in the image on the right] show perimortem chop marks, cut marks, and depression fractures consistent with immobilization and dismemberment."[28]

"Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar."[28]

Younger Dryas[edit | edit source]

Percentages of Neogloboquadrina pachyderma are shown with depth and 14C dates from cores. Credit: Scott J. Lehman & Lloyd D. Keigwin.

The "Alleröd/Younger Dryas transition [occurred] some 11,000 years ago [11,000 b2k]."[29]

From "stable isotope measurements of the pine series (Becker, Kromer & Trimborn 1991) [...] an age of 11,050 cal BP for the beginning of climatic amelioration in central Europe [is obtained]."[26]

Greenlandian[edit | edit source]

Upper Pleistocene[edit | edit source]

Bison occidentalis skull at the Cleveland Museum of Natural History. Credit: Tim Evanson from Cleveland Heights, Ohio, USA.{{free media}}

Neanderthal Man (Homo neanderthalensis) inhabited Eurasia until becoming extinct between 40 and 30 ka.[30][31] Towards the end of the Pleistocene and possibly into the early Holocene, several large mammalian species including the woolly rhinoceros, mammoth, mastodon and Irish elk became extinct.[32]

Cave paintings have been found at Lascaux in the Dordogne which may be more than 17,000 years old. These are mainly of European bison (buffalo), deer and other animals hunted by man. Later paintings occur in caves throughout the world with further examples at Cave of Altamira (Spain) and in India, Australia and the Sahara.[33][34][35]

Magdalenian hunter-gatherers were widespread in western Europe about 18,000 years ago until the end of the Pleistocene. They invented the earliest known harpoons using reindeer horn.[36]

The only domesticated animal in the Pleistocene was the dog, which evolved from the grey wolf into its many modern breeds. It is believed that the grey wolf became associated with hunter-gatherer tribes around 15 ka.[37] The earliest remains of a true domestic dog have been dated to 14,200 years ago.[38] Domestication first happened in Eurasia but could have been anywhere from Western Europe to East Asia.[39] Domestication of other animals such as cattle, goats, pigs and sheep did not begin until the Holocene when settled farming communities became established in the Near East.[37] The cat was probably not domesticated before c. 7500 BC at the earliest, again in the Near East.[40]

A butchered brown bear patella found in Alice and Gwendoline Cave in County Clare and dated to 10,860 to 10,641 BC indicates the first known human activity in Ireland.[41]

The very first human habitation in the Japanese archipelago has been traced to Japanese Paleolithic (prehistoric times) between 40,000 BC and 30,000 BC. The earliest fossils are radiocarbon dated to c. 35,000 BC. Japan was once linked to the Asian mainland by land bridges via Hokkaido and Sakhalin Island to the north, but was unconnected at this time when the main islands of Hokkaido, Honshu, Kyushu and Shikoku were all separate entities.[42]

From about 28 ka, there were migrations across the Bering land bridge from Siberia to Alaska. The people became the Indigenous peoples of the Americas (Native Americans0. It is believed that the original tribes subsequently moved down to Central and South America under pressure from later migrations.[43][44]

In the North American land mammal age scale, the Rancholabrean spans the time from c. 240,000 years ago to c. 11,000 years ago. It is named after the Rancho La Brea fossil site in California, characterised by extinct forms of bison in association with other Pleistocene species such as the mammoth.[45][46][47]

Bison occidentalis and Bison antiquus, an extinct subspecies of the smaller present-day bison, survived the Late Pleistocene period, between about 12 and 11 ka ago. Clovis peoples depended on these bison as their major food source. Earlier kills of camels, horses, and muskoxen found at Wally's beach were dated to 13.1–13.3 ka B.P.[48]

The South American land mammal age Lujanian corresponds with the Late Pleistocene.

There is evidence of human habitation in mainland Australia, Indonesia, New Guinea and Tasmania from c. 45,000 BC. The finds include rock engravings, stone tools and evidence of cave habitation.[49]

Allerød Oscillation[edit | edit source]

Neolithic skull is from the mysterious people that enabled the rise of ancient Egypt. Credit: Joel D. Irish, Jacek Kabacinski, and Czekaj-Zastawny Agnieszka.{{fairuse}}

The "Allerød Chronozone, 11,800 to 11,000 years ago".[29]

"Kamminga and Wright (1988), Wright (1995) and Neves and Pucciarelli (1998) have demonstrated, however, that the Zhoukoudian Upper Cave (UC) cranium 101 display marked similarities with Australo-Melanesians. Cunningham and Wescott (2002) has shown that although highly variable, none of the three specimens from this site (UC 101, UC 102, UC 103) resembles modern Asian populations. Matsumura and Zuraina (1999:333) reported the presence of the “Australo-Melanesian lineage” in Malaysia as late as the terminal Pleistocene. If we consider that UC is dated to between 32,000 BP and 11,000 BP, the fixation of the classical Mongoloid morphology in North Asia could have been a recent phenomenon (terminal Pleistocene/early Holocene), a hypothesis favored by several authors (see Cunningham and Wescott, 2002 for a review)."[50]

"Accordingly, an Australo-Melanesian-like population present in North Asia by the end of the Pleistocene could have been the source of the first Americans. This would explain the presence of a non-Mongoloid morphology in the New World without invoking a direct transpacific route departing from Australia, as suggested by Rivet (1943)."[50]

"Lahr (1995) has argued that human diversity in northern Asia was probably higher in the final moments of the Pleistocene than today, at least as far as cranial morphology is concerned. Therefore, non-Mongoloid Asians could have arrived in the Americas using the Behring Strait as the gate of entry following either the shore of Beringia or a land bridge."[50]

"[Before the pharaohs and pyramids of the Dynastic period starting about 3,100 BC], about 9,300-4,000 BC, enigmatic Neolithic peoples flourished. [It] was the lifestyles and cultural innovations of these peoples that provided the very foundation for the advanced civilisations to come."[51]

Mesolithic[edit | edit source]

This is a tranchet ax from the Mesolithic and it is between 12,000 and 6,000 years old. Credit: Aart Wolters.
The Blytt-Sernander climatic zones have been established with the traditional pollen indicators, as the distinct elm-fall at the Full Atlantic/ Subboreal transition, and the rise of beech at the Subboreal/Subatlantic transition. Credit: N. Schrøder, L. Højlund Pedersen, and R. Juel Bitsch.

The mesolithic period dates from around 13,000 to 8,500 b2k.

"The Siwan people are mostly Berbers, the indigenous people who once roamed the North African coast between Tunisia and Morocco. They inhabited the area as early as 10,000 B.C., first moving toward the coast but later inland as conquering powers pushed them to take refuge in the desert."[52]

"Bruine Bank, an area in the North Sea, is known to fishermen for mainly two things: the excellent catch rates when the weather is cold – and the bones, mammoth teeth, and even artefacts which frequently get caught in the nets [...] The bones, teeth and artefacts stem from a long lost land, Doggerland. Until the end of the last Ice Age, about 8000 years ago, the North Sea was still a part of the continent, even beyond the British Isles. [...] The oldest find is a fragment of a Neanderthal skull which is at least 35,000 years old – possibly even much older, up to 75,000 would be possible. 35,000 old stone tools of the Paleolithic have more than once been dragged inadvertendly to the surface by the fishermen with their mussel vacuum harvesters."[53]

Older Dryas[edit | edit source]

Comparison of the GRIP ice core with cores from the Cariaco Basin shows the Older Dryas. Credit: Konrad A Hughes, Jonathan T. Overpeck, Larry C. Peterson & Susan Trumbore.

"Older Dryas [...] events [occurred about 13,400 b2k]".[54]

"The most negative δ 18O excursions seen in the GRIP record lasted approximately 131 and 21 years for the [inter-Allerød cold period] IACP and [Older Dryas] OD, respectively. The comparable events in the Cariaco basin were of similar duration, 127 and 21 years. In addition to the chronological agreement, there is also considerable similarity in the decade-scale patterns of variability in both records. Given the geographical distance separating central Greenland from the southern Caribbean Sea, the close match of the pattern and duration of decadal events between the two records is striking."[54]

In the figures on the right, especially b, is a detailed "comparison of δ 18O from the GRIP ice core24 with changes in a continuous sequence of light-lamina thickness measurements from core PL07-57PC. Both records are constrained by annual chronologies, although neither record is sampled at annual resolution. The interval of comparison includes the inter-Allerød cold period (12.9-13 cal. kyr BP) and Older Dryas (13.4 cal. kyr BP) events (IABP and OD from a). The durations of the two events, measured independently in both records, are very similar, as is the detailed pattern of variability at the decadal timescale."[54]

Bølling Oscillation[edit | edit source]

The "intra-Bølling cold period [IBCP is a century-scale cold event and the] Bølling warming [occurs] at 14600 cal [calendar years, ~ b2k] BP (12700 14C BP)".[55]

"The second wave to Australia according to the old model were the Carpinterians. They came 10-15,000 YBP and are thought to have come from India. Logically these were Indian Australoid/Veddoid types from the south. All Indians looked like Aborigines (Australoid) until 8,000 YBP. The transition towards Caucasoid only occurred in the last 8,000 years. It may well have been this Carpinterian group that brought the dingo digs along with themselves in a seaward movement to Australia ~13,000 YBP."[56]

"Another group that may well be remnants of the Ancient NE Asians may be the Ainu, but they only showed up 14,000 YBP, and by that time, the Ancient Northeast Race was well underway. However, the Ainuid types seem to have spread out quite a bit. Remains from Northern China from 9,000 YBP appear Ainuid. Ainuid or Australoid types were the first people to come to the Americas. There are a few tribes left who seem to be the remnants of these ancient people. One was an extinct tribe in Baja California called the Guaycuru. I am thinking that the Gilyak may also be part of this ancient race. In phenotype, the Gilyak look more Japanese to me than anything else."[57]

Oldest Dryas[edit | edit source]

Similarities in genes, mutations and random pieces of DNA of Central and South American tribes are mapped with other groups. Warmer colors indicate the strongest affinities. Credit: Pontus Skoglund, Harvard Medical School.{{fairuse}}

"More than 15,000 years ago, humans began crossing a land bridge called Beringia that connected their native home in Eurasia to modern-day Alaska. Who knows what the journey entailed or what motivated them to leave, but once they arrived, they spread southward across the Americas."[58]

Meiendorf Interstadial[edit | edit source]

The Meiendorf Interstadial is typified by a rise in the pollens of dwarf birches (Betula nana), willows (Salix sp.), sandthorns (Hippophae), junipers (Juniperus) and Artemisia.

The beginning of the Meiendorf Interstadial is around 14,700 b2k.

Hasselo stadial[edit | edit source]

The "Hasselo stadial [is] at approximately 40-38,500 14C years B.P. (Van Huissteden, 1990)."[59]

"One of two strongly rounded fragments of the mammoth maxilla from the Shapka Quarry in the southern Leningrad region was recently dated at 38450 + 400/–300 years (GrA-39 116) and rhinoceros remains (spoke bone), back to 38360 + 300/–270 years ago (GrA-38 819) [7]. The maxilla fragments occurred in sediments of the Leningrad Interstadial, which correspond to the transition between the Hasselo Stadial (44–39 ka ago) and the Hengelo Interstadial (38–36 ka ago)."[60]

Marine Isotope Stage 3[edit | edit source]

The site, which dates to approximately 60,000 years ago, is believed to show evidence of hunting by Neanderthals (Homo neanderthalensis). The finds include the in-situ remains of at least nine woolly mammoths (Mammuthus primigenius), associated with Mousterian stone tools and debitage. The artefactual, faunal and environmental evidence were sealed within a Middle Devensian palaeochannel with a dark organic fill. Well preserved in-situ sites of the time are exceedingly rare in Europe and very unusual within a British context.[61]

The site also produced rhinoceros teeth, antlers, as well as other faunal evidence. The stone tools on the site numbered 600, made up of individual artefacts or waste flakes. Particularly interesting were the 44 hand axes of sub-triangular or ovate form.[62]

Marine Isotope Stage 4[edit | edit source]

The glacial episode of Marine Isotope Stage 4, about 57-71,000 years ago, resulted in cooler and drier climatic conditions and the expansion of grassland vegetation. Credit: ROCEEH.{{free media}}

"During the Middle Stone Age of Southern Africa, technological and behavioral innovations led to significant changes in the lifeways of modern humans. The glacial episode of Marine Isotope Stage 4, about 57-71,000 years ago, resulted in cooler and drier climatic conditions and the expansion of grassland vegetation. Sea level dropped by as much as 80 meters below its current level. During this period the cultural phase known as the Howieson’s Poort appeared across much of Southern Africa, peaking at about 60-65,000 years ago, and then disappeared. The lithic industry of the Howieson’s Poort is exemplified by changes in technology, such as the use of the punch technique, an increase in the selection of fine-grained silcrete, and the predominance of retouched pieces including backed tools, segments, scrapers and points. Segments are the type fossil of the Howieson’s Poort and represent multi-purpose armatures that were hafted onto wooden spear shafts. The standardized design and refined style of segments convey information about the behavior of their makers and provide insight about group identity. Increasing use of ochre, the presence of engraved ostrich eggshells, and a bone tool industry are associated with these stone artifacts. Also evident is an intensified use of space. Taken together, these behaviors suggest that the Howieson’s Poort represents a clear marker of modern human culture."[63]

Chibanian[edit | edit source]

The Chibanian, widely known by its previous designation of Middle Pleistocene, is an age in the international geologic timescale or a stage in chronostratigraphy, being a division of the Pleistocene epoch within the ongoing Quaternary period.[64] The Chibanian name was officially ratified in January 2020. It is currently estimated to span the time between 0.770 Ma (770,000 years ago) and 0.126 Ma (126,000 years ago), also expressed as 770–126 ka. It includes the transition in paleanthropology from the Lower Palaeolithic to the Middle Paleolithic over 300 ka.

The Chibanian is preceded by the Calabrian and succeeded by the proposed Tarantian.[65] The beginning of the Chibanian is the Brunhes–Matuyama reversal, when the Earth's magnetic field last underwent reversal.[66] It ends with the onset of the Eemian interglacial period (Marine Isotope Stage 5).[67]

The term Middle Pleistocene was in use as a provisional or "quasi-formal" designation by the International Union of Geological Sciences (IUGS). While the three lowest ages of the Pleistocene, the Gelasian, Calabrian and Chibanian have been officially defined, the Late Pleistocene has yet to be formally defined, along with consideration of a proposed Anthropocene sub-division of the Holocene.[68]

The International Union of Geological Sciences (IUGS) had previously proposed replacement of the Middle Pleistocene by an Ionian Age based on strata found in Italy. In November 2017, however, the Chibanian (based on strata at a site in Chiba Prefecture, Japan) replaced the Ionian as the Subcommission on Quaternary Stratigraphy's preferred GSSP proposal for the age that should replace the Middle Pleistocene sub-epoch.[69] The "Chibanian" name was ratified by the IUGS in January 2020.[64]

The Chibanian includes the transition in paleanthropology from the Lower Palaeolithic to the Middle Palaeolithic: i.e., the emergence of Homo sapiens sapiens between 300 ka and 400 ka.[70] The oldest known human DNA dates to the Middle Pleistocene, around 430,000 years ago. This is the oldest found.[71]

Age paleoclimate glaciation palaeoanthropology
790–761 ka MIS 19 Günz (Elbe) glaciation Peking Man (Homo erectus)
761–712 ka MIS 18
712–676 ka MIS 17
676–621 ka MIS 16
621–563 ka MIS 15 Gunz-Haslach interglacial (Mauer 1) Heidelberg Man (Homo heidelbergensis), Bodo cranium
563–524 ka MIS 14
524–474 ka MIS 13 end of Cromerian (Günz-Mindel) interglacial Boxgrove Man (Homo heidelbergensis)
474–424 ka MIS 12 Anglian Stage in Britain; Haslach glaciation Tautavel Man (Homo erectus)
424–374 ka Marine Isotope Stage 11 (MIS 11) Hoxnian (Britain), Yarmouthian (North America) Swanscombe Man (Homo heidelbergensis)
374–337 ka MIS 10 Mindel glaciation, Elster glaciation, Riss glaciation
337–300 ka MIS 9 Purfleet Interglacial in Britain Mousterian
300–243 ka MIS 8 Irhoud 1 (Homo sapiens); Middle Paleolithic; Haplogroup A (Y-DNA)
243–191 ka MIS 7 Aveley Interglacial in Britain Galilee Man; Haua Fteah
191–130 ka MIS 6 Illinoian Stage Herto Man (Homo sapiens); Macro-haplogroup L (mtDNA); Mousterian
130–123 ka MIS 5e peak of Eemian interglacial sub-stage, or Ipswichian in Britain Klasies River Caves; Sangoan

Illinois Episode glaciations[edit | edit source]

An almost complete adult Homo sapiens mandible is discovered at the Jebel Irhoud site in Morocco. Credit: Jean-Jacques Hublin/Max Planck Institute for Evolutionary Anthropology.{{fairuse}}
A composite reconstruction was made of the earliest known Homo sapiens skull from Jebel Irhoud in Morocco. Credit: Philipp Gunz/Max Planck Institute for Evolutionary Anthropology.{{fairuse}}
Stone tools have been found at the Jebel Irhoud site in the same level as Homo sapiens fossils. Credit: Mohammed Kamal/Max Planck Institute for Evolutionary Anthropology.{{fairuse}}
The Jebel Irhoud site in Morocco is shown. Credit: Shannon McPherron/Max Planck Institute for Evolutionary Anthropology.{{fairuse}}

"Illinoian [is] (ca. 220,000-430,000 yr BP)".[72]

"The [Jebel Irhoud site] Moroccan fossils [...] are roughly 300,000 years old. Remarkably, they indicate that early Homo sapiens had faces much like our own, although their brains differed in fundamental ways."[73]

"We did not evolve from a single 'cradle of mankind' somewhere in East Africa. We evolved on the African continent."[74]

"It now looks like Denisovans can be placed at the site from close to 300,000 years ago to about 50,000 years ago, with Neandertals there for periods in between."[75]

Yarmouthian interglacial[edit | edit source]

"The extinctions and earliest known first occurrences of the 26 extant and 8 extinct cyst taxa in the three samples (with a minimum 430,000 yr BP Yarmouthian age) corroborate a likely assemblages with a maximum age of Illinoian (ca. 220,000-430,000 yr BP) in Unit I."[72]

Aftonian interglacial[edit | edit source]

"The age of the [stag moose Cervalces] roosevelti type specimen is pre-Wisconsin (Aftonian)".[76]

Calabrian[edit | edit source]

"The boundary falls between the highest occurrence of Discoaster brouweri (below) and the lowest common occurrence of left-coiling Neogloboquadrina pachyderma (above), and below the lowest occurrences of medium-sized Gephyrocapsa (including G. oceanica) and Globigerinoides tenellus."[77]

Gelasian[edit | edit source]

Tertiary[edit | edit source]

The Tertiary Period extends from 65.5 ± 0.3 to 2.588 x 106 b2k.

Neogene[edit | edit source]

The Neogene dates from 23.03 x 106 to 2.58 x 106 b2k.

Pliocene[edit | edit source]

The Pliocene ranges from 5.332 x 106 to 2.588 x 106 b2k.

"All of Pliocene time, without a gap, is physically represented in the three stages of which it is composed, in a single demonstrably uninterrupted sequence of highly fossiliferous Upper Cenozoic deep-water strata on the southern coast of Sicily. From bottom to top, the Pliocene consists of the Lower Pliocene Zanclean Stage, with a boundary-stratotype at Eraclea Minoa and a unit-stratotype at Capo Rossello; the Middle Pliocene Piacenzian Stage, defined at Punta Piccola (Castradori et al., 1998); and the Upper Pliocene Gelasian Stage, defined at Monte San Nicola near Gela (Rio et al., 1994, 1998) [...]."[78]

Piacenzian[edit | edit source]

Zanclean[edit | edit source]

Miocene[edit | edit source]

The Miocene dates from 23.03 x 106 to 5.332 x 106 b2k.

Messinian[edit | edit source]

Integrated magnetostratigraphy, calcareous plankton biostratigraphy and cyclostratigraphy of section Oued Akrech is diagrammed. Credit: F.J. Hilgen, S. Iaccarino, W. Krijgsman, G. Villa, C.G. Langereis, and W.J. Zachariasse.{{fairuse}}

"The GSSP of the Messinian Stage, which per definition marks the base of the Messinian and, hence, the boundary between the Tortonian and Messinian Stages of the Upper Miocene Subseries, is Oued Akrech (Morocco) where the Messinian GSSP is now formally designated at the base of the reddish layer of sedimentary cycle no. 15. This point coincides closely with the first regular occurrence (FRO) of the planktonic foraminiferal Globorotalia miotumida group and the first occurrence (FO) of the calcareous nannofossil Amaurolithus delicatus, and falls within the interval of reversed polarity that corresponds to C3Br.1r. The base of the reddish layer and, thus, the Messinian GSSP has been assigned an astronomical age of 7.251 Ma."[79]

Tortonian[edit | edit source]

G. bilaspurensis jaw is displayed. Credit: Ghedoghedo.

The Tortonian lasted from 11.63 Ma to 7.246 Ma.

Gigantopithecus is an extinct genus of ape that existed from perhaps nine million years to as recently as one hundred thousand years ago, at the same period as Homo erectus would have been dispersed,[80] in what is now India, Vietnam, China and Indonesia placing Gigantopithecus in the same time frame and geographical location as several hominin species.[81][82] The primate fossil record suggests that the species Gigantopithecus blacki were the largest known primates that ever lived, standing up to 3 m (9.8 ft) and weighing as much as 540–600 kg (1,190–1,320 lb),[80][83][84][85] although some argue that it is more likely that they were much smaller, at roughly 1.8–2 m (5.9–6.6 ft) in height and 180–300 kg (400–660 lb) in weight.[86][87][88][89]

Middle Miocene[edit | edit source]

The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two faunal stage: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene.

For the purpose of establishing European Land Mammal Ages this sub-epoch is equivalent to the Astaracian age.

Serravallian[edit | edit source]

The top of the Serravallian (the base of the Tortonian stage) is at the last common appearance of calcareous nannoplanktons Discoaster kugleri and planktonic foram Globigerinoides subquadratus. It is also associated with the short normal-polarized chronozone C5r.2n.

The Serravallian is in the middle Miocene and spans the time between 13.82 Ma and 11.63 Ma (million years ago), follows the Langhian and is followed by the Tortonian.[90]

The base of the Serravallian is at the first occurrence of fossils of the nanoplankton species Sphenolithus heteromorphus and is located in the chronozone C5ABr. The official Global Boundary Stratotype Section and Point (GSSP) for the Serravallian is in the 'Ras il-Pellegrin' section, located at the 'Ras il-Pellegrin' headland in the vicinity of 'Fomm ir-Rih' Bay, SW Malta. The base of the Serravallian is represented in the field as the formation boundary between the Globigerina Limestone formation and the Blue Clay formation.[91] The base of the Serravallian is related to the Mi3b oxygen isotope excursion marking the onset of the Middle Miocene Cooling step.

Langhian[edit | edit source]

The top of the Langhian stage (the base of the Serravallian stage) is at the first occurrence of fossils of the nanoplankton species Sphenolithus heteromorphus and is located in magnetic chronozone C5ABr.

The Langhian is, in the International Commission on Stratigraphy (ICS) geologic timescale, an age or stage in the middle Miocene series, spanning the time between 15.97 ± 0.05 Ma and 13.65 ± 0.05 Ma.[92]

The base of the Langhian is defined by the first appearance of foraminifer species Praeorbulina glomerosa and is also coeval with the top of magnetic chronozone C5Cn.1n. A GSSP for the Langhian stage was not yet established in 2009.

The Langhian is coeval with the Orleanian and Astaracian European Land Mammal Mega Zones (more precisely: with biozones MN5 and MN6, MN6 starts just below the Langhian-Serravallian boundary[93]), with the upper Hemingfordian to mid-Barstovian North American Land Mammal Ages,[92] with mid-Relizian to Luisian Californian regional stages (the Luisian extends barely into the early Serravallian[92]), with the early-mid Badenian Paratethys stage of Central and eastern Europe,[93] with the Tozawan stage in Japan (which runs barely into the early Serravallian[92]), with the late Batesfordian through Balcombian to early Bairnsdalian Australian stages[92] and with the mid-Cliffdenian to mid-Lillburnian New Zealand stages.[92]

Burdigalian[edit | edit source]

Aquitanian[edit | edit source]

Paleogene[edit | edit source]

The Paleogene Period extends from 65.5 ± 0.3 to 23.03 ± 0.05 x 106 b2k.[94]

Oligocene[edit | edit source]

The upper boundary of the Oligocene is defined by its GSSP at Carrosio, Italy, which coincides with the first appearance of the foraminiferan Paragloborotalia kugleri and with the base of magnetic polarity chronozone C6Cn.2n.[95]

The Oligocene dates from 33.9 ± 0.1 x 106 to 23.03 x 106 b2k.

The Oligocene Epoch covers 34 - 23 Mya.

The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene.[96]

Oligocene faunal stages from youngest to oldest are:[97][98]

The late Oligocene (26.5 to 24 mya) likely saw a warming trend in spite of low pCO2 levels, though this appears to vary by region.[99] However, Antarctica remained heavily glaciated during this warming period.[100][101] The late Oligocene warming is discernible in pollen counts from the Tibetan Plateau, which also show that the south Asian monsoon had already developed by the late Oligocene.[102]

There appears to have been a land bridge in the early Oligocene between North America and Europe, since the faunas of the two regions are very similar.[103] However, towards the end of the Oligocene, there was a brief marine incursion in Europe.[104][105]

The Eocene-Oligocene transition, peaking around 33.5 mya, was a major cooling event and reorganization of the biosphere.[106][107] The transition is marked by the Oi1 event, in which Marine isotope stages (oxygen isotope ratios) decreased by 1.3 ‰. About 0.3-0.4 ‰} of this is estimated to be due to major expansion of Antarctic ice sheets. The remaining 0.9 to 1.0 ‰ was due to about 5 to 6 °C (9 to 10 °F) of global cooling.[108] The transition likely took place in three closely spaced steps over the period from 33.8 to 33.5 mya. By the end of the transition, sea levels had dropped by 105 meters (344 ft), and ice sheets were 25% greater in extent than in the modern world.[109]

The effects of the transition can be seen in the geological record at many locations around the world. Ice volumes rose as temperature and sea levels dropped.[110] Endorheic basin (Playa) lakes of the Tibetan Plateau disappeared at the transition, pointing to cooling and aridification of central Asia.[111] Pollen and spore counts in marine sediments of the Norwegian-Greenland Sea indicate a drop in winter temperatures at high latitudes of about 5 °C (9.0 °F) just prior to the Oi1 event.[112] Borehole dating from the Southeast Faroes drift indicates that deep-ocean circulation from the Arctic Ocean to the North Atlantic Ocean began in the early Oligocene.[113]

Angiosperms continued their expansion throughout the world as tropical and sub-tropical forests were replaced by temperate deciduous forests. Open plains and deserts became more common and grasses expanded from their water-bank habitat in the Eocene moving out into open tracts.[114] The decline in pCO2 favored C4 photosynthesis,[115] which is found only in angiosperms and is particularly characteristic of grasses.[116] However, even at the end of the period, grass was not quite common enough for modern savannas.[117]

In North America, much of the dense forest was replaced by patchy scrubland with riparian forests.[118][119] Subtropical species dominated with cashews[120] and lychee trees present,[121] and temperate woody plants such as roses, beeches,[122] and pines[123] were common. The legumes spread,[124] while Cyperaceae (sedges)[125] and ferns continued their ascent.[126]

Most extant mammal families had appeared by the end of the Oligocene. These included primitive three-toed horses, rhinoceroses, camels, deer, and peccaries. Carnivores such as dogs, nimravids (ancestor of cats), bears, weasels, and raccoons began to replace the creodonts that had dominated the Paleocene in the Old World. Rodents and rabbits underwent tremendous diversification due to the increase in suitable habitats for ground-dwelling seed eaters, as habitats for squirrel-like nut- and fruit-eaters diminished. The primates, once present in Eurasia, were reduced in range to Africa and South America.[127] Many groups, such as equids,[128] entelodonts, rhinos, merycoidodonts, and camelids, became more able to run during this time, adapting to the plains that were spreading as the Eocene rainforests receded.[129] Brontotheriidae (Brontotheres) died out in the Earliest Oligocene, and creodonts died out outside Africa and the Middle East at the end of the period. Multituberculates, an ancient lineage of primitive mammals that originated back in the Jurassic, also became extinct in the Oligocene, aside from the gondwanatheres.[130]

The Eocene-Oligocene transition in Europe and Asia has been characterized as the Grande Coupure. The lowering of sea levels closed the Turgai Strait across the Obik Sea, which had previously separated Asia from Europe. This allowed Asian mammals, such as rhinoceroses and ruminants, to enter Europe and drive endemic species to extinction.[131] Lesser faunal turnovers occurred simultaneously with the Oi2 event and towards the end of the Oligocene.[132] There was significant diversification of mammals in Eurasia, including the giant indricotheres, that grew up to 6 meters (20 ft) at the shoulder and weighed up to 20 tons. Paraceratherium was one of largest land mammals ever to walk the Earth.[133] However, the indricotheres were an exception to a general tendency for Oligocene mammals to be much smaller than their Eocene counterparts.[134] The earliest deer, giraffes, pigs, and cattle appeared in the mid-Oligocene in Eurasia.[135] The first felid, Proailurus, originated in Asia during the late Oligocene and spread to Europe.[136]

There was only limited migration between Asia and North America.[137] The cooling of central North America at the Eocene-Oligocene transition resulted in a large turnover of gastropods, amphibians, and reptiles. Mammals were much less affected.[138] Crocodilians and pond turtles replaced by dry land tortoises. Molluscs shifted to more drought-tolerant forms.[139] The White River Fauna of central North America inhabited a semiarid prairie home and included entelodonts like Archaeotherium, camelids (such as Poebrotherium), running rhinoceratoids, three-toed equids (such as Mesohippus), nimravids, Protoceratidae (protoceratids), and early canids like Hesperocyon.[140] Merycoidodonts, an endemic American group, were very diverse during this time.[141]

Australia and South American became geographically isolated and developed their own distinctive endemic fauna. These included the New World and Old World monkeys. The South American continent was home to animals such as Pyrotheria (pyrotheres) and Astrapotheria (astrapotheres), as well as litopterns and notoungulates. Sebecosuchians, Phorusrhacidae (terror birds), and carnivorous metatheres, like the Borhyaenidae (borhyaenids) remained the dominant predators.[142]

Africa was also relative isolated and retained its endemic fauna. These included mastodonts, hyraxes, arsinoitheres, and other archaic forms.[143] Egypt in the Oligocene was an environment of lush forested deltas.[144]

At sea, 97% of marine snail species, 89% of clams, and 50% of echinoderms of the Gulf Coast did not survive past the earliest Oligocene. New species evolved, but the overall diversity diminished. Cold-water mollusks migrated around the Pacific Rim from Alaska and Siberia.[145] The marine animals of Oligocene oceans resembled today's fauna, such as the bivalves. Calcareous Cirratulidae (cirratulids) appeared in the Oligocene.[146] The fossil record of marine mammals is a little spotty during this time, and not as well known as the Eocene or Miocene, but some fossils have been found. The baleen whales and toothed whales had just appeared, and their ancestors, the Archaeoceti (archaeocete) cetaceans began to decrease in diversity due to their lack of echolocation, which was very useful as the water became colder and cloudier. Other factors to their decline could include climate changes and competition with today's modern cetaceans and the requiem sharks, which also appeared in this epoch. Early desmostylians, like Behemotops, are known from the Oligocene. Pinnipeds appeared near the end of the epoch from an otter-like ancestor.[147]

Evidence for ocean-wide cooling during the Oligocene exists mostly in isotopic proxies. Patterns of extinction[148] and patterns of species migration[149] can also be studied to gain insight into ocean conditions. For a while, it was thought that the glaciation of Antarctica may have significantly contributed to the cooling of the ocean, however, recent evidence tends to deny this.[150][151]

The lower boundary of the Oligocene (its Global Boundary Stratotype Section and Point or GSSP) is placed at the last appearance of the foraminiferan genus Hantkenina in a quarry at Massignano, Italy. However, this GSSP has been criticized as excluding the uppermost part of the type Eocene Priabonian Stage and because it is slightly earlier than important climate shifts that form natural markers for the boundary, such as the global oxygen isotope shift marking the expansion of Antarctic glaciation (the Oi1 event).[152]

Chattian[edit | edit source]

The Chattian began 27.82 Ma and ended 23.03 Ma.[153]

The top of the Chattian stage (which is the base of the Aquitanian stage, Miocene series and Neogene system) is at the first appearance of foram species Paragloborotalia kugleri, the extinction of calcareous nanoplankton species Reticulofenestra bisecta (which forms the base of nanoplankton biozone NN1), and the base of magnetic C6Cn.2n.

The Chattian is coeval with regionally used stages or zones such as the upper Avernian European mammal zone (it spans the Mammal Paleogene zones 30 through 26 and part of 25[154]); the upper Geringian and lower Arikareean NALMA (mammal zones) of North America; most of the Deseadan SALMA (mammal zone) of South America; the upper Hsandgolian and whole Tabenbulakian Asian Land Mammal Age (mammal zone0 of Asia; the upper Kiscellian and lower Egerian Paratethys stages of Central and eastern Europe; the upper Janjukian and lower Longfordian Australian regional stages; the Otaian, Waitakian, and Duntroonian stages of the New Zealand geologic time scale; and part of the Zemorrian Californian stage and Chickasawhayan regional stage of the eastern US.

The base of the Chattian is at the extinction of the foram genus Chiloguembelina (which is also the base of foram biozone P21b). An official GSSP for the Chattian stage was ratified in October of 2016.

Holarctic-Antarctic Ice Age[edit | edit source]

53 million years ago during the Eocene Epoch, summer high temperatures in Antarctica were around 25 °C (77 °F).[155] Temperatures during winter were around 10 °C (50 °F).[155] It did not frost during the winter.[155] The climate was so warm that trees grew in Antarctica.[155] Arecaceae (palm trees) grew on the coastal lowlands, and Beech Fagus (beech trees) and Pinophyta (conifers) grew on the hills just inland from the coast.[155]

As the global climate became cooler, the planet was seeing a decrease in forests, and an increase in savannas.[156] Animals were evolving to have a larger body size.[156]

The first bovids, kangaroos, and mastodons came about 15 million years ago. This was the warmest part of the Late Cenozoic Ice Age, with average global temperatures around 18.4 °C (65.1 °F).[157] Atmospheric CO2 levels were around 700 ppm.[157] This time period was called the Mid-Miocene Climatic Optimum (MMCO).

The australopithecines first appear in the fossil record around 4 million years ago, and diversified vastly over the next 2 million years. The Mediterranean Sea was dry between 6 and 5 million years ago.[158]

Rupelian[edit | edit source]

The Rupelian began 33.9 Ma and ended 27.82 Ma.[159]

The top of the Rupelian stage (the base of the Chattian) is at the extinction of the foram genus Chiloguembelina (which is also the base of foram biozone P21b).

The base of the Rupelian stage (which is also the base of the Oligocene series) is at the extinction of the foraminiferan genus Hantkenina. An official GSSP for the base of the Rupelian has been assigned in 1992 (Massignano, Italy). The transition with the Chattian has also been marked with a GSSP in August 2017 (Monte Conero, Italy).[160]

The Rupelian overlaps the Orellan, Whitneyan and lower Arikareean North American Land Mammal Ages, the upper Mustersan and Tinguirirican South American Land Mammal Ages, the uppermost Headonian, Suevian and lower Arvernian European Land Mammal Mega Zones (the Rupelian spans the Mammal Paleogene zones 21 through 24 and part of 25[154]), and the lower Hsandgolian Asian Land Mammal Age. It is also coeval with the only regionally used upper Aldingan and lower Janjukian stages of Australia, the upper Refugian and lower Zemorrian stages of California and the lower Kiscellian Paratethys stage of Central and eastern Europe. Other regionally used alternatives include the Stampian, Tongrian, Latdorfian and Vicksburgian.

Eocene[edit | edit source]

The Eocene dates from 55.8 ± 0.2 x 106 to 33.9 ± 0.1 x 106 b2k.

Priabonian[edit | edit source]

The Priabonian began 37.8 Ma and ended 33.9 Ma.[161]

Bartonian[edit | edit source]

The Bartonian began 41.2 Ma and ended 37.8 Ma.[162]

Lutetian[edit | edit source]

The Lutetian began 47.8 Ma and ended 41.2 Ma.[163]

Ypresian[edit | edit source]

The Ypresian began 56.0 Ma and ended 47.8 Ma.[164]

Paleocene[edit | edit source]

The Paleocene dates from 65.5 ± 0.3 x 106 to 55.8 ± 0.2 x 106 b2k.

Thanetian[edit | edit source]

The Thanetian began 59.2 Ma and ended 56.0 Ma.[165]

Selandian[edit | edit source]

The Selandian began 61.6 Ma and ended at 59.2 Ma.[166]

Danian[edit | edit source]

Hoploscaphites constrictus johnjagti subsp. nov., adult macroconchs are ammonites from the Danian. Credit: Marcin Machalski.

"Although crinoids appear not to have been involved in the great change in diversity at the Cretaceous-Paleogene (K-Pg) boundary extinction event, it has been assumed that representatives of order Roveacrinida became extinct during this time. Well-preserved fossils from the Danian (early Paleocene) of Poland demonstrate that these crinoids survived into the earliest Cenozoic."[167]

Post-"Cretaceous ammonites of the genus Hoploscaphites have been found at Stevns Klint in Denmark (Machalski & Heinberg, 2005; Machalski et al., 2009)."[168]

"The maximum age for Danian scaphitid survivors from the Cerithium Limestone at Stevns Klint, Denmark, has recently been estimated to be around 0.2 Ma following the K–Pg boundary event (Machalski and Heinberg in press). Assuming the Cretaceous– Paleogene boundary at 65.4 ± 0.1 Ma (Jagt and Kennedy 1994), the present study covers more than 4 Ma of the final stages in scaphitid evolution."[169]

"Scaphitid material from subunit IVf−7 at the very top of the Meerssen Member [...] traditionally regarded to be uppermost Maastrichtian, has recently been reassigned to the lowermost Danian, based on microfossil and strontium isotope evidence (Smit and Brinkhuis 1996). According to Jagt et al. (2003), the scaphitid and baculitid ammonites preserved in subunit IVf−7 are early Danian survivors."[169]

Above center are Hoploscaphites constrictus johnjagti subsp. nov., adult macroconchs, ammonites from the Danian: A. MGUH 27366, lowermost Danian, Stevns Klint, Denmark, in apertural (A1), lateral (A2, A3), and ventral (A4) views.

San Juan Basin[edit | edit source]

The images show the right femur of a hadrosaurian dinosaur from the San Juan River site. Credit: JE Fassett, SG Lucas, RA Zielinski, and JR Budahn.

"[P]ollen was the more accurate age indicator and therefore the Ojo Alamo dinosaurs were Paleocene in age. The conclusion was tentative because Paleocene pollen nowhere occurred at exactly the same locality as dinosaur bone. Paleocene pollen is present, however, in the Ojo Alamo near Barrel Spring, within one mile of the Alamo Wash bone locality [...]."[170]

"A Cretaceous dinosaur bone collected from just below the Cretaceous-Paleogene interface yielded a U-Pb date of 73.6 ± 0.9 Ma, in excellent agreement with a previously determined 40Ar/39Ar date of 73.04 ± 0.25 Ma for an ash bed near this site. The second dinosaur bone sample from Paleocene strata just above the Cretaceous-Paleogene interface yielded a Paleocene U-Pb date of 64.8 ± 0.9 Ma, consistent with palynologic, paleomagnetic, and fossil-mammal biochronologic data."[171]

"The second bone sample BB-1, a fragment of a large sauropod femur (Alamosaurus sanjuanensis) was collected from the Paleocene Ojo Alamo Sandstone. This bone shows much less geochemical variation than bone 22799-D and is very well preserved. The weighted average 206Pb/238U date of 64.8±0.9 Ma is interpreted to record the time of bone fossilization. Considering that fossilization times are typically less than a few thousand years, the age result from BB-1 confirms the existence of Paleocene dinosaurs. The strontium isotopic composition of both bones are relatively unradiogenic (0.70811±3 and 0.70860±3, respectively). The strontium content of both bones is remarkably homogeneous, in contrast to the chemical variability displayed by most elements, therefore we interpret the strontium isotope values to reflect the indigenous bone composition."[172]

The right femur of the hadrosaurian dinosaur is shown at left where the bone is in place in A and after excavation, preparation, and mounting in B.

Basque Coast Geopark[edit | edit source]

"In this environment, [...] sediments and rocks that are rich in microfossils that were deposited between 66.4 and 65.4 Ma, a time interval that includes the known Cretaceous/Paleogene boundary (K/Pg) [were analyzed]. Dated in 66 Ma, the K/Pg boundary divides the Mesozoic and Cenozoic eras and it coincides with one of the five large extinctions of the planet."[173]

"Thanks to these periodicities identified in the Zumaia sediments, we have been able to determine the most precise dating of the climatic episodes that took place around the time when the last dinosaurs lived."[174]

"Carbon-13 isotopic analysis on the rocks in combination with the study of planktonic foraminifera ─microfossils used as high-precision biostratigraphic indicators─ has made it possible to reconstruct the paleoclimate and chronology of that time in the Zumaia sediments. More than 90% of the Cretaceous planktonic foraminiferal species from Zumaia became extinct 66 Ma ago, coinciding with a big disruption in the carbon cycle and an accumulation of impact glass spherules originating from the asteroid that hit Chicxulub, in the Yucatan Peninsula (Mexico)."[173]

Maastrichtian[edit | edit source]

Biostratigraphic chart of the Upper Cretaceous (Campanian and Maastrichtian) of the Western Interior of North America showing ammonite and inoceramid zones. Credit: Neil H. Landman, W. James Kennedy, Neal L. Larson, Joyce C. Grier, James W. Grier, and Tom Linn.{{fairuse}}
Photograph is of a fossil cast of a Baculites grandis shell taken at the North American Museum of Ancient Life. Credit: Ninjatacoshell.{{free media}}
Baculites baculus type specimen to allow field identification present in the Cretaceous of the Western Interior Seaways. Credit: Cretaceous Atlas of Ancient Life.{{fairuse}}

Extends from 70.6 ± 0.6 to 65.5 ± 0.3 Mya.

The center is a fossil cast of a Baculites grandis shell taken at the North American Museum of Ancient Life.

Baculites baculus, type specimen in the image at right, lower boundary of zone and lower boundary for Maastrichtian dated to 70.6 ± 0.6 Ma and upper boundary dated to 70.00 ± 0.45 Ma.[175]

Edmontonian[edit | edit source]

Didymoceras cheyennense (Meek & Hayden, 1856) is a fossil ammonite from the Cretaceous of South Dakota, USA. Credit: James St. John.{{free media}}
Piceance Basin stratigraphy, ammonite zones are for the Campanian only (Edmontonian not labelled) and inferred ages. Credit: Michael H. Hofmann, Anton Wroblewski and Ron Boyd.{{fairuse}}

Edmontonian extends from 80.8 to 70.7 Mya.

The fossil shown on the right has a bizarre and irregularly shaped shell. Such examples are called heteromorph ammonites.

Classification: Animalia, Mollusca, Cephalopoda, Ammonoidea, Ancyloceratina, Nostoceratidae.

"The Williams Fork Formation represents a period spanning seven ammonite zones from the Didymoceras cheyennense to the Baculites baculus (Meek and Hayden, 1861) Zone (Newman, 1987). Based on the timescale of Obradovich and Cobban (1975), these seven ammonite zones represent approximately three million years, correlative with the late Campanian to early Maastrichtian (Harland et al., 1990). Lillegraven and Ostresh (1990) correlated these seven ammonite zones to the Edmontonian North American Land Mammal Age (NALMA)."[176]

Other ammonite zones include Baculites compressus from the Fruitland Formation above the Didymoceras cheyennense zone.[177] "Baculites compressus age is from a bentonite bed in the Bearpaw Shale, Big Horn County, Montana (Obradovich, 1993 and written communication, Obradovich, 1996)."[177]

The stratigraphic column on the left shows ammonite zones between Didymoceras nebrascense and the Maastrichtian with inferred ages.

Bentonite "marker beds are found throughout the lowermost Williams Fork Formation and the underlying Cameo Coal interval [...] the Yampa ash marker bed, is found near the top of the Cameo Coal interval, suggesting a depositional age equal to or younger than 72.2 ± 0.1 Ma for the lower Williams Fork Formation [...] and time equivalent to the previously mentioned Baculites reesidei zone (Brownfield and Johnson 2008) [...]."[178]

Campanian[edit | edit source]

Stratigraphic column for the Tuscaloosa is shown below the Eutaw. Credit: Richard B. Powers, USGS.{{free media}}
This is a 2.7 cm section of Baculites compressus. Credit: Kevmin.{{free media}}
A specimen of Placenticeras ammolite from the Bearpaw Formation. Credit: James St. John.{{free media}}

The Bearpaw Formation is famous for its well-preserved ammonite fossils. These include Placenticeras meeki and Placenticeras intercalare, and the baculite Baculites compressus.[179]

Extends from 83.5 ± 0.7 to 70.6 ± 0.6 Mya.

The Baylis Formation, Post Creek Formation and the Tuscaloosa Formation are Upper Cretaceous from the Campanian.

Middle Cenomanian[edit | edit source]

The hierarchy of ammonites in the Middle Cenomanian is shown on the left below beginning at 95.73 ± 0.61.[180]

Subdivisions of the Middle Cenomanian
Period Western Interior Ammonite
Taxon Range Zones
Age Ma Species image
>94.71 ± 0.49
Plesiacanthoceras wyomingense is from the late Cretaceous in Wyoming, USA. Credit: Ryan Somma.{{free media}}
<94.96 ± 0.50
Acanthoceras amphibolum Zone is Middle Cenomanian starting at 94.96 ± 0.50 Ma. Credit: Cretaceous Atlas of Ancient Life.{{fairuse}}
<95.73 ± 0.61
Acanthoceras bellense Zone is Middle Cenomanian starting at 95.73 ± 0.61 Ma. Credit: Cretaceous Atlas of Ancient Life.{{fairuse}}
<95.73 ± 0.61
Acanthoceras muldoonense Zone is Middle Cenomanian. Credit: Cretaceous Atlas of Ancient Life.{{fairuse}}
<95.73 ± 0.61
Acanthoceras granerosense Zone is Middle Cenomanian. Credit: Cretaceous Atlas of Ancient Life.{{fairuse}}
<95.73 ± 0.61
Conlinoceras tarrantense Zone is Middle Cenomanian. Credit: Cretaceous Atlas of Ancient Life.{{fairuse}}
Fossil shell of Acanthoceras rhotomagensis from France, on display at Gallery of Paleontology and Comparative Anatomy in Paris. Credit: Hectonichus.{{free media}}

Shells of Acanthoceras rhotomagensis may reach a diameter of about 36–50 centimetres (14–20 in). Their shells have ornate ribs.[181][182]

Acanthoceras rhotomagensis fossils may be found in Western Europe and western North America.[183]

Acanthoceras rhotomagensis fossils occur in the Middle Cenomanian just above the boundary with the Lower Cenomanian.[184]

The "highly fossiliferous marl, 1 m in thickness, is the Cast Bed of Price (1877), [where the] lowest record of Acanthoceras rhotomagensis (Brongniart)" occurs.[184]

Cenomanian[edit | edit source]

The Cenomanian per the International Commission on Stratigraphy is the oldest or earliest age of the Late Cretaceous or the lowest stratigraphic stage of the Upper Cretaceous.[90]

As a unit of geologic time measure, the Cenomanian age spans the time between 100.5 ± 0.9 Ma and 93.9 ± 0.8 Ma, preceded by the Albian and is followed by the Turonian, where the Upper Cenomanian starts approximately at 95 Ma.[185]

The base of the Cenomanian is placed at the first appearance of foram species Rotalipora globotruncanoides in the stratigraphic record, located in an outcrop at the western flank of Mont Risou, near the village of Rosans in the French Alps (département Hautes-Alpes, coordinates: 44°23'33"N, 5°30'43"E), in the reference profile, located 36 meters below the top of the Marnes Bleues Formation.[186]

Jurassic[edit | edit source]

This is an example of Neophyllites antecedens showing suture marks. Credit: Günter Knittel.{{fairuse}}

The Jurassic/Cretaceous boundary occurs at 144.2 ± 2.6 Ma (million years ago).[90]

Perisphinctes tiziani is an index fossil for the Jurassic.[187]

Toarcian[edit | edit source]

The top of the stage is at the first appearance of ammonite genus Leioceras.

The Toarcian, in the International Commission on Stratigraphy (ICS) geologic timescale, an age and stage in the Early or Lower Jurassic, spans the time between 182.7 Ma and 174.1 Ma.[188] It follows the Pliensbachian and is followed by the Aalenian.[189]

The base of the Toarcian is defined as the place in the stratigraphic record where the ammonite genus Eodactylites first appears, a GSSP for the base is located at Peniche, Portugal.

Pliensbachian[edit | edit source]

Pleuroceras spinatum Museum of Toulouse.

The Pliensbachian, an age of the geologic timescale and stage in the stratigraphic column, is part of the Early or Lower Jurassic epoch or series and spans the time between 190.8 ± 1.5 Ma and 182.7 ± 1.5 Ma.[188] The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.[190]

The base of the Pliensbachian is at the first appearances of the ammonite species Bifericeras donovani and genera Apoderoceras and Gleviceras, with The Wine Haven profile near Robin Hood's Bay (Yorkshire, England) has been appointed as global reference profile for the base (GSSP).[191]

The Pliensbachian contains five ammonite biozones in the boreal domain:

  • zone of Pleuroceras spinatum
  • zone of Amaltheus margaritatus
  • zone of Prodactylioceras davoei
  • zone of Tragophylloceras ibex
  • zone of Uptonia jamesoni

In the Tethys Ocean domain, the Pliensbachian contains six biozones:

  • zone of Emaciaticeras emaciatum
  • zone of Arieticeras algovianum
  • zone of Fuciniceras lavinianum
  • zone of Prodactylioceras davoei
  • zone of Tragophylloceras ibex
  • zone of Uptonia jamesoni

The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of Bifericeras donovani and of genus Apoderoceras the defining biological marker for the start of the Pliensbachian Stage of the Jurassic, 190.8 ± 1.0 million years ago.[192]

Hettangian[edit | edit source]

Psiloceras spelae tirolicum has its first occurrence at the Triassic-Jurassic boundary as geochron for the base of the Jurassic. Credit: Axel von Hillebrandt et al.
Fossil shell of Psiloceras planorbis from Germany, on display at Galerie de paléontologie et d'anatomie comparée in Paris. Credit: Hectonichus.
In this image of the Kuhjoch East section, the "Golden Spike" is at the Triassic-Jurassic boundary. Credit: Axel von Hillebrandt et al.

"Since the 1960’s, the LO (lowest occurrence) of the ammonite Psiloceras (usually the species P. planorbis [first image on the right]) has provided the working definition of the TJB (e.g., Lloyd, 1964; Maubeuge, 1964; Cope et al., 1980; Warrington et al., 1994; Gradstein et al., 2004)."[193]

"The Global Stratotype Section and Point (GSSP) defining the base of the Jurassic System Lower Jurassic Epoch and Hettangian Stage is situated at the Kuhjoch pass, Karwendel Mountains, Northern Calcareous Alps, Austria (47°29'02"N/11°31'50"E). The Triassic-Jurassic (T-J) boundary is exposed at Kuhjoch West and at Kuhjoch East [in the second image on the right], and corresponds to the first occurrence (FO) of the ammonite Psiloceras spelae tirolicum [at the top of this section]."[194]

Another FO is that of "the aragonitic foraminifer Praegubkinella turgescens"[194]

The Triassic/Jurassic boundary occurs at 205.7±4.0 Ma (million years ago).[90]

Triassic[edit | edit source]

Trophites subbuliatus is an index fossil for the Triassic.[187]

Induan[edit | edit source]

The diagram shows the Permian-Triassic boundary at the base of the Induan. Credit: Yin Hongfu, Zhang Kexin, Tong Jinnan, Yang Zunyi and Wu Shunbao.
Hindeodus parvus is now recognized as the index fossil, occurring in the Zone above the P-T boundary. Credit: Yin Hongfu, Zhang Kexin, Tong Jinnan, Yang Zunyi and Wu Shunbao.

In the diagram on the right, the Permian-Triassic boundary is at the base of the Induan limestone that occurs within the Yinkeng Formation.

"The Global Stratotype Section and Point (GSSP) of the Permian-Triassic boundary [...] is defined at the base of Hindeodus parvus horizon, i.e. the base of Bed 27c of Meishan section D, Changxing County, Zhejiang Province, South China."[195]

"Hindeodus parvus is now recognized as the index fossil" occurring in the Zone above the P-T boundary.[195]

The Induan was the earliest part of the Triassic Period, and lasted from about 251.2 to about 251.902 Ma.

Gangetian[edit | edit source]

This chart shows the stratigraphic position of the Aegean in the Middle Triassic. Credit: Heinz W. Kozur & Gerhard H. Bachmann.

The chart above indicates that the Gangetian is in the Brahmanian.

The Permian/Triassic boundary occurs at 248.2 ± 4.8 Ma (million years ago).[90]

Devonian[edit | edit source]

Geodized brachiopod fossil lined with calcite, with a single crystal of sphalerite, is from the Devonian of Wisconsin. Credit: Kennethcgass.{{free media}}

In the image on the right, a geodized brachiopod fossil is lined with calcite with a single crystal of sphalerite; Middle Devonian; Milwaukee Formation; Lindwurm Member; Milwaukee County, Wisconsin; MPM P29133; collected by K.C. Gass; photograph originally published in K.C. Gass, J. Kluessendorf, D.G. Mikulic, and C.E. Brett, 2019. Fossils of the Milwaukee Formation: A Diverse Middle Devonian Biota from Wisconsin, USA. Siri Scientific Press, Manchester, UK.

Silurian[edit | edit source]

The Silurian spanned 443.7 ± 1.5 to 416.0 ± 2.8 Mb2k.

Hexamoceras hertzeri is an index fossil for the Silurian.[187]

Hexamoceras is a genus of the Nautiloidea.[196]

"Rolfe made the important observation that 'Other genera are pre-Devonian and hence cannot be ammonoid aptychi, but Ruedemann's suggestion that aptychi "would naturally also have existed in the Ordovician and Silurian cephalopods" has been largely overlooked'."[197]

Ordovician[edit | edit source]

Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era, which spans 41.6 million years from the end of the Cambrian Period 485.4 million years ago (Mya) to the start of the Silurian Period 443.8 Mya.[198]

Himantian[edit | edit source]

Katian[edit | edit source]

External mold of the Upper Ordovician bivalve Anomalodonta gigantea from the Waynesville Formation of Franklin County, Indiana. Credit: Wilson44691.{{free media}}

Sandbian[edit | edit source]

Nemagraptus gracilis, Sandbian graptolites, are from the Caparo Formation, Venezuelan Andes. Credit: J.C. Gutiérrez-Marco, D. Goldman, J. Reyes-Abril, and J. Gómez.

"The Lower Sandbian Nemagraptus gracilis Zone comprises one of the most widespread, and easily recognizable graptolite faunas in the Ordovician System. The base of the N. gracilis Zone also marks the base of the Upper Ordovician Series".[199]

The Sandbian was the last stage of the Upper Ordovician

Darriwilian[edit | edit source]

Dapingian[edit | edit source]

Floian[edit | edit source]

Ibexian[edit | edit source]

North American Stage: Ibexian (491 - 471.8 ± 1.6 Ma).

End Defined By: Conodont, potentially lowest occurrence of Protoprioniodus aranda or of Baltoniodus triangularis.

Tremadocian[edit | edit source]

Upper Cambrian[edit | edit source]

~497 – 485.4 ± 1.9 Ma.

"Cambrian Radiolaria are best known from Middle Cambrian shallow-water carbonate environments (i.e., the Middle Cambrian strata; Won and Below, 1999), but they are also known Upper Cambrian in deep-sea deposits (Tolmacheva et al., 2001)."[200]

  • Elvinia-zone Upper Cambrian.

New Elvinia Zone (Upper Cambrian) Trilobites.[201]

Upper Middle Cambrian.[202]

A "radiometrically anchored astrochronologic framework across the late Cambrian interval, using high-resolution aluminum (Al) series (1 mm resolution) through the Alum Shale Formation in Scania, southernmost Sweden, [is] based on the fully cored Albjära-1 well. Significant cycles with periods of 405 kyr (long eccentricity), 108 kyr (short eccentricity), 30.4 kyr (obliquity) and 18.8 kyr (precession), associated with long-term amplitude modulation of obliquity and precession, confirmed the orbital imprint on late Cambrian climate. Using the U-Pb dating at 486.78±0.53Ma for the Cambro-Ordovician boundary as anchor point, our timescale spans from ~483.9 to ~500.0 Ma, covering 7 trilobite superzones and 3 graptolite zones. The calibration indicates ages of 491.2±0.54 Ma, 493.9±0.67 Ma, 497.3±0.67 Ma and 500.4±0.67 Ma for the lower boundaries of provisional Stage10, Jiangshanian, Paibian and Guzhangian stages, respectively."[203]

Cambrian[edit | edit source]

The Cambrian lasted from 542.0 ± 1.0 to 488.3 ± 1.7 Mb2k.

Trilobite zones allowing biostratigraphic correlation in the Cambrian belong to the Lower, Middle, or Upper Cambrian.

Trilobites are used as index fossils to subdivide the Cambrian period. Assemblages of trilobites define trilobite zones.[204]

Series Stage Trilobite zone Trilobite GSSP
Furongian Cambrian Stage 10 Saukia-zone (upper part), Eurekia apopsis-zone, Tangshanaspis-zone, Parakoldinioidia-zone, Symphysurina-zone[205] Lotagnostus americanus (undecided)
Jiangshanian Ellipsocephaloides-zone, Saukia-zone (lower part) [205] Agnostotes orientalis
Paibian ? (?) Glyptagnostus reticulatus
Miaolingian Guzhangian Bolaspidella ( / Ptychagnostus praecurrens ?? ).[206] Lejopyge laevigata
Drumian Ptychagnostus atavus
Wuliuan Bathyuriscus–Elrathina (?) Oryctocephalus indicus
Cambrian Series 2 Cambrian Stage 4 Olenellus Olenellus or Redlichia (undecided)
Cambrian Stage 3
Fallotaspis, Nevadella First appearance of trilobites (undecided)
Terreneuvian (Pre-Trilobitic Cambrian) Cambrian Stage 2 ?

Collier Shale[edit | edit source]

The Collier Shale, a geologic formation in the Ouachita Mountains of Arkansas and Oklahoma, dating from the Late Cambrian to Early Ordovician periods, the oldest stratigraphic unit exposed in Arkansas, first described in 1892,[207] named in 1909,[208][209] with assigned type locality to the headwaters of Collier Creek in Montgomery County, Arkansas, underlies the Crystal Mountain Sandstone.


  • Anechocephalus aphelodermus[201]
  • Apachia lumaleasa[210]
  • Buttsia drabensis[211]
  • Cernuolimbus monilis[201]
  • Cheilocephalus brachyops[211]
  • Cliffia lataegenae[211]
  • Cliffia magnacilis[210]
  • Comanchia amplooculata[211]
  • Dellea planafrons[210]
  • Dellea suada[211]
  • Erixanium lacunatum[201]
  • Housia vacuna[211]
  • Iddingsia hapsis[210]
  • Irvingella major[211]
  • Jessievillia radiatus[210]
  • Kindbladia wichitaensis[211]
  • Kymagnostus harti[210]
  • Linnarsonella girtyi[211]
  • Neoagnostus dilatus[210]
  • Parabolinoides contractus[211]
  • Pseudagnostus communis[211]
  • Pseudokingstonia exotica[211]
  • Pterocephalia sanctisabae[211]
  • Pulchricapitus fetosus[210]
  • Pyttstrigis dicilia[210]
  • Xenocheilos minutum[211]

Stage 10[edit | edit source]

Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series that follows the Jiangshanian and precedes the Ordovician Tremadocian Stage.[212]

The upper boundary is defined as the appearance of the conodont Iapetognathus fluctivagus which marks the beginning of the Tremadocian and is radiometrically dated as 485.4 Ma.[213]

The calibration indicates an age of 491.2±0.54 Ma for the lower boundary of provisional Stage10.[203]

Batyrbayan[edit | edit source]

Russian-Kazakhian Stage: Batyrbayan (491.5 - 488.3 Ma)

The Batyrbayan is the lowest level of the Upper Cambrian.

Biostratigraphic zones:[214]

  1. Lotagnostus hedini
  2. HarpidoidesPlatypeltoides
  3. Lophosaukia

Croixan[edit | edit source]

501 ± 2 to 488.3 ± 1.7 Ma.

End Defined By: Conodont, lowest occurrence of Iapetognathus fluctivagus; just above base of Cordylodus lindstromi conodont Zone. Just below lowest occurrence of planktonic graptolites.

The lower and upper stages of the North American Upper Cambrian is the Croixan Series.

Late Cambrian Epoch (Upper Cambrian, Merioneth, Furongian, Croixian, Potsdamian), from 501 ± 2 to 488.3 ± 1.7 Ma.

Start Defined By: Trilobite, lowest occurrence of agnostoid Glyptagnostus reticulatus. Coincides with base of large positive carbon-isotope excursion.

Merioneth[edit | edit source]

501 ± 2 to 488.3 ± 1.7 Ma.

  • Genevievella campbellina occurs in the Upper Cambrian of the United States (Merioneth: Warriorsmark, Huntingdon, Huntingdon; Warrior Formation, near Waddle, Centre County, all Pennsylvania, 40.8° N, 77.9° W)[215]

Jiangshanian[edit | edit source]

~494 – ~489.5 Ma.

The upper boundary candidate is the FAD of the Trilobite Lotagnostus americanus.

The Jiangshanian is the middle stage of the Furongian series following the Paibian Stage and is succeeded by the Cambrian Stage 10, with the base defined as the first appearance of the trilobite Agnostotes orientalis which is estimated to be the 494 million years ago, lasting until approximately 489.5 Ma.[216]

The Global Standard Stratotype-Section and Point (GSSP) for the Base of the Jiangshanian Stage was established in 2011.[217]

Aksayan[edit | edit source]

Russian-Kazakhian Stage: Aksayan (493 - 491.5 Ma).

Biostratigraphic zones:[214]

  1. Trisulcagnostus trisulcus
  2. Lotagnostus scrobicularis
  3. Neoagnostus quadratiformis
  4. Eurudagnostus ovaliformis
  5. Eurudagnostus kazachstanus
  6. Pseudagnostus pseudangustilobis

Plicatolina lucida from the Aksayan Stage, Ogon’or Formation, upper part.[214]

"Cambrian deposits appear on the surface in wings of anticline folds (Chekurovka and Bulkur Anticlines). The Upper Cambrian is represented by most of the upper part of the Ogon’or Formation. In the north of the region, in the Bulkur Anticline, the upper Ogon’or Formation is replaced by dolomites of the Balaganakh Formation (Kembrii Sibiri (Cambrian of Siberia), Repina, L.N. and Rozanov, A.Yu., Eds., Tr. Inst. Geol. Geofiz., Ross. Akad. Nauk, Sib. Otd., no. 788, Novosibirsk: Nauka, 1992). All records of the genus Plicatolina are confined to the upper part of the Ogon’or Forma􏰀tion."[214]

Steptoean[edit | edit source]

Steptoan North American Stage, from 494.5 to 493 Ma.

Lower Millardan

The Steptoean Positive Carbon Isotope Excursion (SPICE) was a geological event which occurred ~ 500 Ma. The SPICE event was a positive shift in carbon isotope (Δ13
) values which lasted for around 2 to 4 million years.[218] This shift is interpreted to be a global disturbance in the carbon cycle, affecting both the ocean and atmosphere. Regional sea level changes and trilobite extinctions are associated with the SPICE event, although the exact mechanism(s) driving these events is still unconfirmed.[219][220]

One proposed cause of the SPICE is an increase in the burial of organic carbon, perhaps caused by increased primary productivity or enhanced organic matter preservation due to ocean stratification (i.e. anoxia or euxinia).[221][222]

"The Cambrian Paibian sedimentary succession of the central Australian Amadeus Basin contains a sequence of supratidal to subtidal shallow marine siliciclastic and oolitic, stromatolitic limestones and dolostones. Basin-wide sequence stratigraphy in combination with biostratigraphy revealed the [Glyptagnostus] G. stolidotus Zone within a 3rd-order transgressive systems tract (TST). The westward transgression caused changes from a fluvial-dominated depositional environment towards a shallow-marine oolitic carbonate shoal environment. The eastern succession is dominated by stromatolitic, oolitic carbonate rocks with 2- to 5-m 5th-order shoaling upward cycles with several 4th-order cycles. The change from TST to HST (highstand systems tract) is marked by a maximum flooding surface within the Goyder Formation, which coincides with the peak of the Steptoean Positive Carbon Isotope Excursion (SPICE). The SPICE shows a facies-independent, synchronous positive δ13
excursion of 5‰ in a 130 m interval in 8 sections across a ~460 km transect. The SPICE peak is lowest in the nearshore successions (+0.4‰ δ13
), and highest in the platform succession (+4.9‰ δ13
) and is interpreted to be related to the chemical gradient of seawater and mixing of the [dissolved inorganic carbon] DIC with atmospheric CO
-derived (i.e. terrestrial) bicarbonate. The recovery from SPICE is recorded by 4th-order shoaling upward cycles that compose the 3rd-order HST."[223]

Sakian[edit | edit source]

Russia, Kazakhstan age Sakian (494.5 - 493) Ma.

Biostratigraphical zones:[214]

  1. Ivshinagostus ivshini
  2. Oncagnostus longiformis
  3. Glyptagnostus reticulatus

Ayusokkanian[edit | edit source]

Russian-Kazakhian Stage: Ayusokkanian (501 - 494.5 Ma).

The FAD of Lotagnosthus americanus is the primary stratigraphic tool for correlation of the base for Stage 10.[217]

Biostratigraphic zones:[214]

  1. Glyptagnostus stolidotus
  2. Kormagnostus simplex

Paibian[edit | edit source]

Glyptagnostus reticulatus angelini - holotype is by Allison R. Palmer, 1962. Credit: Allison R. Palmer.{{free media}}

ICS Stage: Paibian (501 - 496 Ma).

The "FAD of Glyptagnostus reticulatus [is the primary stratigraphic tool for correlation of the base] for the Paibian Stage."[217]

Dresbachian[edit | edit source]

This figure shows the genus extinction intensity, i.e. the fraction of genera that are present in each interval of time but do not exist in the following interval. Credit: Rursus{{free media}}
A Cedaria minor trilobite, 11 mm, Order Ptychopariida, Family Cedariidae, collected from the Weeks Formation, House Range, Millard County, Utah, USA, from the early Upper Cambrian. Credit: Dwergenpaartje.{{free media}}
A Genevievella granulosa trilobite, 18 mm, Order Ptychopariida, Family Llanoaspididae was collected from the Weeks Formation, House Range, Millard County, Utah, USA, early Upper Cambrian. Credit: Dwergenpaartje.{{free media}}

The Dresbachian is a Maentwrogian regional stage of North America, lasting from 501 to 497 Ma,[224] part of the Upper Cambrian and is defined by four trilobite zones (Cedaria, Crepicephalus, Aphelaspis, and Dunderbergia), overlaps with the International Commission on Stratigraphy (ICS)-stages Guzhangian, Paibian and the lowest Jiangshanian.

The Dresbachian overlies the Middle Cambrian Albertan series, and is the lowest stage of the Upper Cambrian Croixian series, followed by the Franconian stage. The Dresbachian extinction event, about 502 million years ago, was followed by the Cambrian–Ordovician extinction event about 485.4 Ma.

  • Cedaria is a small, rather flat trilobite with an oval outline, a headshield and tailshield of approximately the same size, 7 articulating segments in the middle part of the body and spines at the back edges of the headshield that reach halflength of the body, that lived during the early part of the Upper Cambrian (Dresbachian), and is especially abundant in the Weeks Formation.[225]
  • Genevievella simon, Genevievella cuniculaena, Genevievella raggedi and Genevievella campbellina have been found in the Upper Cambrian of Canada (Dresbachian, Rabbitkettle Formation, Yukon, 62.7° N, 128.4° W).[226]
  • Genevievella spinox has been excavated from the Upper Cambrian of the United States (Dresbachian, Coosella zone, Riley Formation, Central Texas, 30.3° N, 97.7° W)[227]
  • Genevievella granulosa, Weeks Formation, House Range, Millard County, Utah, USA, early Upper Cambrian.

Mindyallan[edit | edit source]

Upper Cambrian of Australia: 501 - 497 Ma.

  • Genevievella caelata is known from the Upper Cambrian of Australia (Mindyallan, Upper beds Member, Mungerbar Formation, Glenormiston, Queensland, 22.9° S, 138.8° E).[228]

Marjuman[edit | edit source]

Cambrian Faunas of China include number 4 Bathyuriscus manchuriensis Walcott. Credit: Charles Doolittle Walcott.{{free media}}

North American Stage: Marjuman (504 - 494.5 Ma).

Cedaria-zone lowermost Upper Cambrian

Bathyuriscus is an extinct genus of Cambrian trilobite, a nektobenthic predatory carnivore, endemic to the shallow seas that surrounded Laurentia.[229] Its major characteristics are a large forward-reaching glabella, pointed pleurae or pleurae with very short spines, and a medium pygidium with well-impressed furrows. Complete specimens have never reached the size of 7 cm predicted by the largest pygidium found. Bathyuriscus is often found with the free cheeks shed, indicating a ecdysis (moulted exoskeleton).[230] An average specimen will in addition have a furrowed glabella, crescent-shaped eyes, be semi-circular in overall body shape, have 7 to 9 thoracic segments, and a length of about 1.5 inches.[231]

Guzhangian[edit | edit source]

The image shows exposure of the GSSP for the base of the Guzhangian Stage (coinciding with the FAD of Lejopyge laevigata) in the Huaqiao Formation, Luoyixi section, Guzhang County, Hunan Province, China. Credit: Shanchi Peng, Loren E. Babcock, Jingxun Zuo, Huanling Lin, Xuejian Zhu, Xianfeng Yang, Richard A. Robison, Yuping Qi, Gabriella Bagnoli, and Yong’an Chen.
The image shows an exoskeleton of the cosmopolitan agnostoid trilobite Lejopyge laevigata. Credit: Shanchi Peng et al.

~500.5 – ~497 Ma

The Guzhangian-Paibian boundary is marked by the first appearance of the trilobite Glyptagnostus reticulatus around 497 Ma.[232]

"The Global boundary Stratotype Section and Point (GSSP) for the base of the Guzhangian Stage (Cambrian Series 3) is defined at the base of a limestone (calcisiltite) layer 121.3 m above the base of the Huaqiao Formation in the Louyixi section along the Youshui River (Fengtan Reservoir), about 4 km northwest of Luoyixi (4 km southeast of Wangcun), in northwestern Hunan, China."[233]

"The GSSP level [for the Guzhangian] contains the lowest occurrence of the cosmopolitan agnostoid trilobite Lejopyge laevigata [in the image on the left] (base of the L. laevigata Zone)."[233]


  • Glyptagnostus reticulatus zone around 497 Ma.[232]
  • Glyptagnostus stolidotus zone.[234]
  • Lejopyge laevigata zone.[233]
  • Genevievella bigranulosa is present in the Upper Cambrian of China (Guzhangian, Glyptagnostus stolidotus trilobite zone and Paibian, Glyptagnostus reticulatus trilobite zone, both Huaqiao Formation, Hunan, 28.4° N, 109.5° E).[234]

Miaolingian[edit | edit source]

~509 – ~497 Ma.

Upper GSSP acceptance date is 2003.[235]

The Miaolingian lasted from about 509 to 497 Ma and is divided in ascending order into 3 stages: the Wuliuan, Drumian, and Guzhangian.

The most promising fossil markers were seen to be the respective first appearances of either trilobite species Ovatoryctocara granulata or Oryctocephalus indicus,[236] which both have an age close to 509 Ma.[237] After some deliberation, the FAD of Oryctocephalus indicus was chosen to be the lower boundary marker, and the GSSP was placed in Wuliu-Zengjiayan, Guizhou, China.[238]

Miaolingian acceptance date is 2018.[238]

Albertan[edit | edit source]

Albertan, 509 ± 1.0 to 497 ± 1.7 Ma.

In the local North American subdivision, a paleontologist finding fragments of the trilobite Olenellus would identify the beds as being from the Waucoban Stage whereas fragments of a later trilobite such as Elrathia would identify the stage as Albertan.

In some of these subdivisions the Cambrian is divided into three epochs with locally differing names – the Early Cambrian (Caerfai or Waucoban, 541 ± 1.0 to 509 ± 1.7 mya), Middle Cambrian (St Davids or Albertan, 509 ± 1.0 to 497 ± 1.7 mya) and Furongian (497 ± 1.0 to 485.4 ± 1.7 mya; also known as Late Cambrian, Merioneth or Croixan).

Spence Shale[edit | edit source]

Hyolithe is within the Spence Shale. Credit: Mark A. Wilson.{{free media}}

(~507.5-506 Ma)

The Spence Shale, Wuliuan, ~507.5-506 Ma, the middle member of the Langston Formation in southeastern Idaho and northeastern Utah, exposed in the Bear River Range, the Wasatch Range and the Wellsville Mountains, is known for its abundant Cambrian trilobites and the preservation of Burgess Shale-type fossils,[239] type locality: Spence Gulch in southeastern Idaho, near the town of Liberty, first described in 1908,[240] spans the Albertella and Glossopleura biozones.[239]

  • Glossopleura-zone
  • Albertella-zone

Sonoraspis and Albertella[241]

Wheeler Shale[edit | edit source]

Elrathia kingii (trilobite) is from the Wheeler Shale (Middle Cambrian), Utah. Credit: Wilson44691.{{free media}}
Itagnostus interstictus - Wheeler Shale, Utah, USA - Cambrian period (≈ -507 MA) is at 39.25°N 113.33°W. Credit: Parent Géry.{{free media}}
An Asaphiscus wheeleri trilobite, Order Ptychopariida, Family Asaphiscidae, 25 mm measured along the axis, Collected from the Wheeler Formation, Millard County, Utah, USA, from the Middle Cambrian (Drumian). Credit: Dwergenpaartje.{{free media}}

(~507 Ma)

Asaphiscus wheeleri occurs in the Middle Cambrian of the United States (Delamaran, Lower Wheeler Shale, Millard County, Utah, 40.0°N, 113.0°W;[242] and Menevian, Wheeler Formation, House Range, Utah, 39.2° N, 113.3° W).[243]

Burgess Shale[edit | edit source]

Trilobites: Bathyuriscus rotundatus and Ogygopsis klotzi are from the Burgess Shale. Credit: Matteo De Stefano/MUSE.{{free media}}
The photo shows the Walcott Quarry Shale Member of the Burgess Shale (Middle Cambrian), British Columbia. Credit: Mark A. Wilson.{{free media}}

Def. a "rock formation in the Canadian Rockies that contains very many fossils from the Cambrian period"[244] is called the Burgess Shale.

The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada.[245][246] It is famous for the exceptional preservation of the soft parts of its fossils. At 508 Ma (Wuliuan of the middle Cambrian),[247] it is one of the earliest fossil beds containing soft-part imprints.

(~508 Ma)

Bathyuriscus–Elrathina-zone Middle Cambrian

Contemporaneous with the Burgess Shale

Oryctocephalus indicus-zone underlies Burgess Shale.

Drumian[edit | edit source]

Correlation chart of the Cambrian shows the new global chronostratigraphic stage (Drumian; column at left) compared to regional usage in major areas of the world. Credit: Loren E. Babcock, Richard A. Robison, Margaret N. Rees, Shanchi Peng, and Matthew R. Saltzman.

~504.5 – ~500.5 Ma

The "FAD of Ptychagnostus atavus [is the primary stratigraphic tool for correlation of the base (GSSP)] for the Drumian Stage".[235]

"The Global boundary Stratotype Section and Point (GSSP) for the base of the Drumian Stage (Cambrian Series 3) is defined at the base of a limestone (calcisiltite) layer 62 m above the base of the Wheeler Formation in the Stratotype Ridge section, Drum Mountains, Utah, USA. The GSSP level contains the lowest occurrence of the cosmopolitan agnostoid trilobite Ptychagnostus atavus (base of the P. atavus Zone)."[248]

Middle Cambrian[edit | edit source]

The Middle Cambrian corresponds to the Miaolingian.

Epoch: Middle Cambrian (513 - 501 Ma).

Ptychagnostus is a member of the Agnostida that lived during the Cambrian, did not exceed one centimetre in length.[249] Their remains are rarely found in empty tubes of the polychaete worm Selkirkia.[250] The genus probably ranged throughout the water column, had two glabellar lobes, and three pygidial lobes.[251]

Ptychagnostus punctuosus-zone[206]

  • Ptychagnostus punctuosus (Type species).
  • Ptychagnostus affinis (formerly Pt. punctuosus affinis)
  • Ptychagnostus aculeatus
  • Ptychagnostus akanthodes
  • Ptychagnostus atavus
  • Ptychagnostus cassis
  • Ptychagnostus ciceroides
  • Ptychagnostus cuyanus
  • Ptychagnostus germanus
  • Ptychagnostus gibbus
  • Ptychagnostus hybridus
  • Ptychagnostus intermedius
  • Ptychagnostus michaeli
  • Ptychagnostus praecurrens
  • Ptychagnostus seminula

Mayan[edit | edit source]

Russian-Kazakhian Stage: Mayan (502 - 501 Ma).


  1. Peronopsis earliest Mayan (~497.5 Ma) to earliest Batyrbayan (~497.0 Ma)
  2. Peronopsis bonnerensis = Pentagnostus (Meragostus) bonnerensis - zone
  3. Lejopyge laevigataAldanaspis truncata[214]
  4. Anomocarioides limbataeformis[214]
  5. Corynexochus perforatusAnopolenus henrici[214]

Amgan[edit | edit source]

Amgan Russian-Kazakhian Stage (Solvan), from 513 ± 2 to 502 Ma.

"The Lower Cambrian carbonate sequence ends with the 160-m-thick Upper Toyonian Barangol Formation, the age which is based on calcareous algae, archaeocyatids and trilobites (Zybin et al., 2000). It is uncorformably overlain by the Ust’-Sema Formation, a 1,000-m-thick basaltic sequence displaying thick conglomerates at its base, containing blocks of limestones with a similar fauna to the one identified in the Cheposh Formation (Zybin et al., 2000)."[200]

Biostratigraphic zones:[214]

  1. Pseudanomocarina
  2. Kounamkites
  3. Schistocephalus

Wuliuan[edit | edit source]

Observed stratigraphic distribution of trilobites in the lower Wheeler Formation near the base of the Ptychagnostus atavus Zone, Stratotype Ridge section, Drum Mountains, Utah, USA, is modified from Babcock et al., 2004. Credit: Loren E. Babcock, Richard A. Robison, Margaret N. Rees, Shanchi Peng, and Matthew R. Saltzman.
Key agnostoid trilobite species are used for recognition of the base of the Drumian Stage. Credit: Loren E. Babcock, Richard A. Robison, Margaret N. Rees, Shanchi Peng, and Matthew R. Saltzman.

~509 – ~504.5 Ma


Starts at the base of the Drumian stage.[252]

"The polymerid trilobites Ptychoparella (incorporating Elrathina as a junior synonym) and Elrathia have long stratigraphic ranges (Robison, 1964a, 1964b, 1976; Babcock, 1994a) that extend from stage 5 into the lower part of the Drumian Stage (White, 1973) and provide little help in constraining the base of the Drumian."[248]

On the right are images of key agnostoid trilobite species used for recognition of the base of the Drumian Stage.

"A, Ptychagnostus gibbus (Linnarsson), dorsal exoskeleton in shale, x 8.4, from the Wheeler Formation, c. 25 m above base, south side of Swasey Peak, House Range, Utah (R. A. Robison locality 157); KUMIP 153949. B, Ptychagnostus atavus (Tullberg), cephalon in limestone showing scrobiculate genae, x 8.1, from the Wheeler Formation, 27 m above base, House Range, Utah (R. A. Robison locality 196); KUMIP 153830. C, P. atavus (Tullberg), pygidium in limestone, x 7.8, from same locality as specimen in Figure 6B; KUMIP 153933. D, P. atavus (Tullberg), dorsal exoskeleton from shale with cone-in-cone calcite encrusting ventral surface, x 8.1 from the Wheeler Formation, c. 100 below top, “Swasey Spring quarry”, east flank of House Range, Utah (R. A. Robison locality 114); KUMIP 153930."[248]

The "Cambrian lobopodian (panarthropod) worm Hallucigenia sparsa [is] from the Burgess Shale (Cambrian Series 3, Stage 5)."[253]

Pioche Shale[edit | edit source]

The Pioche Shale is an Early to Middle Cambrian Burgess shale-type Lagerstätte in Nevada.[254]

It spans the Early–Middle Cambrian boundary; fossils from the Early Cambrian are preserved in botryoidal hematite, whereas those from the Middle Cambrian are preserved in the more familiar carbon films, and very reminiscent of the Chengjiang County preservation.[254]

It preserves arthropods and worms familiar from the Burgess Shale.[255]

It spans the early Cambrian Olenellus and basal Middle Cambrian Eokochaspis nodosa trilobite zones.[255]

Eokochaspis zone.

Lower Cambrian[edit | edit source]

541.0 ± 1.0 – ~509 Ma.

"The Lower Cambrian carbonate sequence ends with the 160-m-thick Upper Toyonian Barangol Formation, the age which is based on calcareous algae, archaeocyatids and trilobites (Zybin et al., 2000)."[200]

Early Cambrian[edit | edit source]

In some subdivisions the Cambrian is divided into three epochs with locally differing names; e.g. the Early Cambrian (Caerfai or Waucoban, 541 ± 1.0 to 509 ± 1.7 mya).

Early Cambrian Epoch (Lower Cambrian, Caerfai, Waucoban, Georgian), from 542 ± 0.3 to 513 ± 2 Ma. Start Defined By: Trace fossil, lowest occurrence of Treptichnus (Phycodes) pedum. Near base of negative carbon-isotope excursion.

Stage 4[edit | edit source]

~514 – ~509 Ma.

The lower boundary may be the first appearance datum of two trilobite genera, Olenellus or Redlichia or the first appearance of the trilobite species Arthricocephalus chauveaui,[256] which set the lower boundary close to 514 Ma.[237] The upper boundary corresponds to the beginning of the Wuliuan.

Olenellus zone (top of the Lower Cambrian)

The Olenellus-zone has traditionally marked the top of the Lower Cambrian.[257]

Subdivision of the Olenellus-zone

Recently, it has been proposed to subdivide the Olenellus-zone.[258]

The following zones have been proposed to replace the Upper Olenellus-zone. Each lower boundary is defined by the first occurrence of the naming species. Each upper boundary is defined by the first occurrence of the naming species of the overlying zone. In case of the youngest zone, this is Eokochaspis nodosa, that also marks the base of the Wuliuan.

  • Nephrolenellus multinodus-zone (youngest).

Species: Nephrolenellus multinodus (lower half), Mesonacis fremonti, Olenellus terminatus Sensu and its common qualifiers (s.l.), Olenellus puertoblancoensis s.l., Olenellus fowleri s.l., Olenellus gilberti, Bolbolenellus brevispinus (not the lower part), Olenellus chiefensis (upper half), Olenellus sp.1 (upper half), Nephrolenellus geniculatus (upper part), Olenellus sp.2 (upper part), Olenellus howelli (very uppermost part).

  • Bolbolenellus euryparia-zone.

Species: Bolbolenellus euryparia (lower half), Mesonacis fremonti, Bristolia fragilis s.l. (lower half), Olenellus terminatus s.l., Olenellus fowleri s.l., Olenellus puertoblancoensis s.l., Olenellus gilberti (uppermost part), Biceratops nevadensis (uppermost part), Bristolia brachyomma (very uppermost part).

  • Peachella iddingsi-zone

Species: Peachella iddingsi (lower half), Mesonacis fremonti, Olenellus nevadensis (lower part), Bristolia anteros (lowest half), Bristolia fragilis s.l., Olenellus terminatus s.l., Paranephrolenellus besti (very short period in the late lower part), Peachella brevispina (middle part).

  • Bristolia insolens-zone

Species: Bristolia insolens (lower half), Mesonacis fremonti, Olenellus nevadensis, Olenellus clarki, Olenellus sp.3, Paranephrolenellus klondykensis (lowest part), Bristolia harringtoni (middle part), Bristolia bristolensis (lower half), Bristolia anteros (not lowest part), Bristolia fragilis s.l. (upper half), Paranephrolenellus inflatus (very short interval in the middle), Eopeachella angustispina (uppermost part).

  • Bristolia mohavensis-zone

Species: Bristolia mohavensis (lower half), Mesonacis fremonti, Olenellus nevadensis, Olenellus clarki, Olenellus sp.3, Bristolia harringtoni (middle part), Bristolia bristolensis (upper half).

  • Arcuolenellus arcuatus-zone (oldest)

Species: Arcuolenellus arcuatus (lowest part), Arcuolenellus aff. megafrontatis (lower half), Mesonacis cylindricus (not the highest part), Olenellus nevadensis, Olenellus clarki (not lowest part), Mesonacis fremonti (upper half), Olenellus sp.3 (upper part).

Dyeran[edit | edit source]

North American Stage: Dyeran (524.5 - 512 Ma).

"Six new biostratigraphic zones are established within the upper part of the Dyeran Stage: the Arcuolenellus arcuatus (oldest), Bristolia mohavensis, Bristolia insolens, Peachella iddingsi, Bolbolenellus euryparia, and Nephrolenellus multinodus (youngest) zones. The base of each zone is defined by the first appearance datum of the eponymous species. Sequence stratigraphic analysis reveals the presence of four depositional sequences within the upper Dyeran of the southern Great Basin. Sequence boundaries are often marked by erosion surfaces within successions deposited on the craton and the inner and middle shelf, but do not show strong association with observed range ends of olenelloid species and do not correspond to zonal boundaries within the upper Dyeran. Sequence I spans the A. arcuatus Zone to the lowermost Bo. euryparia Zone; Sequence II is contained entirely within the Bo. euryparia Zone; Sequence III spans the upper part of the Bo. euryparia Zone and lower part of the N. multinodus Zone; and Sequence IV corresponds to the upper part of the N. multinodus Zone."[258]

  1. Nephrolenellus multinodus
  2. Bolbolenellus euryparia
  3. Peachella iddingsi
  4. Bristolia insolens
  5. Bristolia mohavensis
  6. Arcuolenellus arcuatus

Latham Shale[edit | edit source]

Bristolia trilobite zone, Latham Shale Formation, Dyeran (516.0 - 513.0 Ma).

Trilobites found throughout the Latham Shale are from the Bristolia subzone of the Bonnia-Olenellus Zone, indicating that the Latham Shale belongs to the upper Dyeran Stage of the Waucoban Series.

Longwangmioan[edit | edit source]

China Stage, from 518 to 513 Ma.

Toyonian[edit | edit source]

Toyonian Russian-Kazakhian Stage, from 518.5 to 513 ± 2 Ma.

"Trilobite associations found in [the Shashkunar] Formation belong to the Lower Toyonian ParapoliellaOnchocefalina zone. Archaeocyathids and brachiopods found in this formation suggest a wider, but compatible, Botomian to Toyonian age (Zybin et al., 2000). The Lower Cambrian carbonate sequence ends with the 160-m-thick Upper Toyonian Barangol Formation, the age which is based on calcareous algae, archaeocyatids and trilobites (Zybin et al., 2000). It is uncorformably overlain by the Ust’-Sema Formation, a 1,000-m-thick basaltic sequence displaying thick conglomerates at its base, containing blocks of limestones with a similar fauna to the one identified in the Cheposh Formation (Zybin et al., 2000)."[200]

"The up to 700-m-thick Cheposh Formation, composed of massive limestones made of archaeocyathid biohermes, overlies conformably the Shashkunar Formation. Trilobite associations found in this Formation belong to the Lower Toyonian Parapoliella–Onchocefalina zone. Archaeocyathids and brachiopods found in this formation suggest a wider, but compatible, Botomian to Toyonian age (Zybin et al., 2000). The Lower Cambrian carbonate sequence ends with the 160-m-thick Upper Toyonian Barangol Formation, the age which is based on calcareous algae, archaeocyatids and trilobites (Zybin et al., 2000). It is uncorformably overlain by the Ust’-Sema Formation, a 1,000-m-thick basaltic sequence displaying thick conglomerates at its base, containing blocks of limestones with a similar fauna to the one identified in the Cheposh Formation (Zybin et al., 2000)."[200]

Biostratigraphic zones:[214]

  1. Anabaraspis splendens
  2. Lermontovia grandis
  3. Bergeroniellus ketemensis

Lenian[edit | edit source]

Regional Stage: Lenian (524 - 513 Ma).

Waucoban[edit | edit source]

Early Cambrian Epoch (Lower Cambrian, Caerfai, Waucoban, Georgian), from 542 ± 0.3 To 513 ± 2 Ma. Start Defined By: Trace fossil, lowest occurrence of Treptichnus (Phycodes) pedum. Near base of negative carbon-isotope excursion.

In North America, the Lower Cambrian is called the Waucoban series that is then subdivided into zones based on the succession of trilobites.

In East Asia and Siberia, the same unit is split into Alexian, Atdabanian, and Botomian stages.

Caerfai[edit | edit source]

Early Cambrian Epoch (Lower Cambrian, Caerfai, Waucoban, Georgian), from 542 ± 0.3 to 513 ± 2 Ma. Start Defined By: Trace fossil, lowest occurrence of Treptichnus (Phycodes) pedum. Near base of negative carbon-isotope excursion.

Stage 3[edit | edit source]

~521 – ~514 Ma.

The FAD of trilobites is the primary stratigraphic tool for correlation of the base for Stage 3.[256]

Changlangpuan[edit | edit source]

Changlangpuan Chinese Stage, from 523 to 518 Ma.

The Changlangpuan in China is comparable to the Botomian in Russia or Kazakhian.

Botomian[edit | edit source]

Botomian Russian-Kazakhian Stage, from 524 to 518.5 Ma.

The end-Botomian mass extinction event, also known as the late early Cambrian extinctions, refer to two extinction intervals that occurred during Stages 4 and 5 of the Cambrian Period, approximately 513 to 509 million years ago. Estimates for the decline in global diversity over these events range from 50% of marine genera[259] up to 80%.[260] Among the organisms affected by this event were the small shelly fossils, Archaeocyatha (archaeocyathids) (an extinct group of sponges), trilobites, brachiopods, Hyolitha (hyoliths), and Mollusca (mollusks).[259][261][262][263]

"The Botomian age is based essentially on trilobites (ParapagetiaSerrodiscus zone), but also on archaeocyathids".[200]

"Relatively well-preserved polycystine Radiolaria are [...] described from Lower Cambrian (Botomian) strata of the Shashkunar Formation, Altai Mountains in southern Siberia (Russia)."[200]

Shashkunar Formation[edit | edit source]

"The Shashkunar Formation, a 500 m thick Lower Cambrian sequence of essentially carbonate rocks, overlies unconformably the Manzherok Formation and displays at its base a thick sequence of conglomerates. It is composed essentially of thin-bedded grey to dark grey limestones with interbedded nodular chert levels which become more frequent towards the top of the Formation."[200]

"These radiolarians display a test formed of a disorderly and three-dimensionally interwoven meshwork of numerous straight and curved bars branching from a five-rayed point-centered spicule located within the inner shell surface. The shell structure allows their assignment to the family Archeoentactiniidae, thus extending the known age range of the family down to the Lower Cambrian."[200]

The "material obtained from Altai attests that the earliest representatives of the family Archeoentactiniidae originated during or before the Botomian."[200]

"[M]icrofossil material from nodular cherts of Botomian slope carbonates of the Shashkunar Formation can be assigned to the Archeoentactiniid family."[200]

Biostratigraphic zones:[214]

  1. Bergeroniaspis ornata
  2. Bergeroniellus asiaticusi
  3. Bergeroniellus ketemensis
  4. Bergeroniellus gurari
  5. Bergeroniellus micmacciformisErbiella

Heatherdale Shale[edit | edit source]

A bentonite/volcanic tuff bed in the Heatherdale Shale dates to 522 million years ago. Credit: James St. John.{{free media}}
Structurally-tilted mudrocks are in the Cambrian of South Australia. Credit: James St. John.{{free media}}

Heatherdale Shale is in the upper Normanville Group, mid-Botomian Stage, upper Lower Cambrian.

One soft-bodied fossil has been discovered from this site - a poorly-preserved Isoxys valve was cracked out in the lab. Isoxys is a nonmineralizing bivalved arthropod known only from Lower and Middle Cambrian rocks.

"Only two of several tuffaceous horizons from the Stansbury and Arrowie Basins have been dated (i) a date of 522.0 ± 2.1 Ma from the Heatherdale Shale of the Stansbury Basin, about 400 m above latest Atdabanian archaeocyathids and (ii) a date of 522.0 ± 1.8 Ma from the lower part of the Billy Creek Formation in the Arrowie Basin. Neither date is regarded as reliable."[264]

"In the Stansbury Basin, Cooper et al. (1992) produced a mean 206 Pb/238 U Sensitive High Mass Resolution Ion Microprobe (SHRIMP) age of 526 ± 4 Ma with standard SL13 on zircons separated from a tuff bed within the upper part of the Heatherdale Shale at Sellicks Hill, Fleurieu Peninsula. Further analysis, plus new zircon data, enabled Jenkins et al. (2002) to revise this age to 522 ± 2.0 Ma. However, this age is not very well biostratigraphically constrained in the area of outcrop. It is overlain unconformably by the thick (∼8–10 km), predominantly flyschoid sediments of the Kanmantoo Group that contains very few, poorly preserved trilobites and brachiopods (Jago and Haines, 1997). The Kanmantoo Group is intruded by an early syntectonic granitoid known as the Rathjen Gneiss, which has a U–Pb date of 514 ± 4 Ma (Foden et al., 1999)."[264]

"The tuff horizon is quite close to the only known trilobite fauna within the Heatherdale Shale. This comprises a few poorly preserved specimens of the trilobite Atops briandailyi (Jago et al., 1984; Jenkins and Hasenohr, 1989; Jenkins et al., 2002). The tuff horizon is over 400 m stratigraphically higher than the only reasonably well constrained biostratigraphic horizon in the Fleurieu Peninsula Cambrian succession. This horizon contains archaeocyaths in the top of the Sellick Hill Formation and the bottom part of the Fork Tree Limestone that Zhuravlev and Gravestock (1994) considered to be latest Atdabanian. Based on both biostratigraphy and sequence stratigraphy, Gravestock (1995) correlated the Heatherdale Shale with the biostratigraphically controlled successions of Yorke Peninsula and the Flinders Ranges. He suggested that the Heatherdale Shale should be correlated with the Mernmerna Formation and Oraparinna Shale that contain Pararaia janeae Zone (equivalent to the Botoman) trilobites in the Central Flinders Ranges."[264]

"With respect to Yorke Peninsula, Gravestock (1995) correlated the upper Heatherdale Shale to the upper part of the Koolywurtie Member of the Parara Limestone; this contains archaeocyaths of the Syringocnema favus beds, implying a middle to late Botoman age (Zhuravlev and Gravestock, 1994). This is supported by the work of Zhou and Whitford (1994) who reported a U–Pb age of 525 ± 8 Ma with standard SL13 from a felsic tuff within the Cymbric Vale Formation of western New South Wales; Jenkins et al. (2002) recalculated this age to 517.8 ± 2.1 Ma. Both archaeocyath (Zhuravlev and Gravestock, 1994) and trilobite faunas (Jago et al., 1997; Paterson, 2005) from the Cymbric Vale Formation support a mid to late Botoman age."[264]

Terreneuvian[edit | edit source]

541.0 ± 1.0 – ~521 Ma.

The Terreneuvian Series includes Cambrian Stage 2 and the Fortunian Stage.[256]

Stage 2[edit | edit source]

Hallucigenia sparsa is from the Burgess Shale. Credit: Jean-Bernard Caron, Martin R. Smith, and Thomas H. P. Harvey.

~529 – ~521 Ma.

"Hallucigeniids are [...] an important and widespread component of disparate Cambrian communities from late in the Terreneuvian (Cambrian Stage 2) through the ‘middle’ Cambrian (Series 3); their apparent decline in the latest Cambrian may be partly taphonomic. The cone-in-cone construction of hallucigeniid sclerites is shared with the sclerotized cuticular structures (jaws and claws) in modern onychophorans."[253]

In the image on the right "Hallucigenia sparsa [is] from the Burgess Shale: (a,b) Smithsonian Institution, National Museum of Natural History (NMNH) 83935 (holotype), articulated specimen, showing seven pairs of spines, partially decayed towards the rear, presumed head to the right. (a) composite image of part and counterpart; (b) enlargement of the basal part of the spines; (c,d) Royal Ontario Museum (ROM) 61513, complete specimen showing seven pairs of spines and backscatter image of boxed area (d); (e–i) ROM 57776, backscatter images (overview and close-ups of boxed areas) of spine showing four internal cones and lineations; (g) ROM 61513, backscatter image showing lineations and a distal cone; (j–o) ROM 62269, backscatter images of several spines, showing elemental distribution of carbon (l) and phosphorous (m) and details of ornamentation near spines’ mid-length (n) and base (o) (arrows indicate local disturbances in the rhomboid pattern); (p) ROM 61513, backscatter image showing details of ornamentation showing scales in positive relief (top left) and negative relief below the carbon film. Ba, basal region of spines; C, cone; Li, lineations. Scale bars: (a–d) 1000 µm; (e,j–m) 100 µm; (f–i) 50 µm; (n–p) 10 µm."[253]

Atdabanian[edit | edit source]

Nevadella eucharis is from the Lower Cambrian: Mahto formation. Credit: Charles Doolittle Walcott.{{free media}}

Russian-Kazakhian Stage: Atdabanian (530 - 524 Ma).

"[S]ponge spicules and protoconodonts, characteristic of the Upper Atdabanian and Botomian stages, as well as radiolarians were found in the siliceous mudstone lenses of this formation (Obut and Iwata, 2000, Zybin et al., 2000)."[200]


  • Nevadella eucharis is known from the Middle Member of the Poleta Formation, Esmeralda County, Nevada, USA.[265]
  • Nevadella keelensis is known from the Sekwi Formation, Northwest Territories, Canada.[266][267]
  • Nevadella mountjoyi is known from the Mural Formation, north slope of Mount Mumm, Alberta, Canada.[268]
  • Nevadella perfecta is known from the Mahto Formation, Mumm Peak on the west side of Hitka Pass, western Alberta, Canada.[269]

Biostratigraphic zones:[214]

  1. JudomiaUktaspis (Prouktaspis)
  2. Delgadella anabara
  3. Repinaella
  4. Profallotaspis jakutensis

Montezuman[edit | edit source]

Montezuman North American Stage, from 529.5 to 524.5 Ma.

  1. Nevadella eucharis and/or Nevadella perfecta
  2. Nevadia addyensis
  3. Avefallotaspis Maria
  4. Grandinasus patula
  5. Esmeraldina rowei

Qungzusian[edit | edit source]

Qungzusian Chinese Stage, from 532 to 523 Ma.

Fortunian[edit | edit source]

541.0 ± 1.0 – ~529 Ma.

The FAD of Trichophycus pedum is the primary stratigraphic tool for correlation of the base (GSSP) for the Fortunian Stage.[256]

Tommotian[edit | edit source]

Tommotian Russian-Kazakhian Stage, from 534 to 530 Ma.

Manzherok Formation[edit | edit source]

Biostratigraphic zones:[214]

  1. Dokidocyathus lenaicusTumuliolinthus primigenius
  2. Dokidocyathus regularis
  3. Nochoroicyathus sunnaginicus

Meishuchuan[edit | edit source]

Treptichnus pedum fossil marks the Cambrian-Ediacaran GSSP. Credit: Martin Smith.{{free media}}

Chinese Stage: Meishuchuan (542 - 532 Ma).

Nemakit-Daldynian[edit | edit source]

Nemakit-Daldynian Russian-Kazakhian Stage, from 542 ± 0.3 To 534 Ma. Start Defined By: Trace fossil, lowest occurrence of Treptichnus (Phycodes) pedum. Near base of negative carbon-isotope excursion.

Baratal Formation[edit | edit source]

The "Baratal Formation [is] made essentially of thick-bedded partly stromatolitc limestones".[200]

The "Baratal Formation contains microphytolites of a Vendian age (Buslov et al., 1993, Zybin and Sergeev, 1978)."[200]

Eskongo Formation[edit | edit source]

"The Eskongo Formation contains microphytolites, calcareous algae and shelly microfauna characteristic of a Vendian-Early Cambrian age (Terleev, 1991). A lot of sponge spicules (Protospongia sp. and Chancelloria sp. and specimens of Monaxonellida, Hexactinellida and Tetraxonida) were also identified in the siliceous levels of this Formation (Zybin et al., 2000)."[200]

Upper Adelaidean[edit | edit source]

Early Adelaidean stratigraphic column of Umberatana and Wilpena Groups show locations of ages. Credit: K.H. Mahan, B.P. Wernicke, and M.J. Jercinovic.{{fairuse}}

The Adelaidean appears to encompass the Delamerian Granites and the Adelaide Rift Complex.

"The deposits include the type sections for the often globally correlated Sturtian and Marinoan glacial sequences (e.g., Preiss, 2000) and the Global Stratotype Section and Point (GSSP) for the newly defined Ediacaran Period (Knoll et al., 2004)."[270]

The later Adelaidean includes the Burra and Caliana Groups.[270]

Ediacaran[edit | edit source]

Dickinsonia is a 558-million-year-old oval-shaped creature that may have borne a superficial resemblance to a segmented jellyfish. Credit: Ilya Bobrovskiy.{{fairuse}}
Amongst the depositional sequences of the Ediacaran and Cambrian is the Ediacaran base GSSP. Credit: James G. Gehling and Mary L. Droser.

"The fossils [of Dickinsonia] were unearthed at Zimnie Gory in the White Sea area of north-west Russia."[271]

"The fossil fat molecules that we've found prove that animals were large and abundant 558 million years ago, millions of years earlier than previously thought."[272]

"Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Ediacaran Biota were. The fossil fat now confirms Dickinsonia as the oldest known animal fossil, solving a decades-old mystery that has been the Holy Grail of palaeontology."[272]

Def. "a geologic period within the Neoproterozoic era from about 620 to 542 million years ago"[273] is called the Ediacaran.

Gaskiers[edit | edit source]

Deposits attributed to the Gaskiers — assuming that they were all deposited at the same time — have been found on eight separate paleocontinents, in some cases occurring close to the equator (at a latitude of 10-30°). The 300 m-thick name-bearing section at Gaskiers (Newfoundland) is packed full of striated dropstones.[274] Its δ13C values are very low (pushing 8‰), consistent with a period of environmental abnormality.[274] The bed lies just below some of the oldest fossils of the Ediacaran biota, leading to early suggestions that the passing of the glaciation may have paved the way for the evolution of these odd organisms. More accurate dating methods have shown that there is in fact a 9 million year gap between the diamictites and the 570 Ma macrofossils.[274]

Marinoan[edit | edit source]

The Marinoan glaciation was a period of worldwide glaciation that lasted from approximately 650 to 632.3 ± 5.9 Ma (million years ago)[275] during the Cryogenian geologic period. The end of the glaciation might have been hastened by the release of methane from equatorial permafrost.[276][277]

Elatina glaciation[edit | edit source]

"The Elatina glaciation has not been dated directly, and only maximum and minimum age limits of c. 640 and 580 Ma, respectively, are indicated."[278]

Cryogenian ice age[edit | edit source]

Def. "a geologic period within the Neoproterozoic era from about [720] to 600 million years ago"[279] is called the Cryogenian.

Glaciers extended and contracted in a series of rhythmic pulses, supported by microfossil lineages, possibly reaching as far as the equator.[280]

Abundant "agglutinated tests in organic-rich carbonates directly overlying Sturtian glacial deposits [found] from two different paleocontinents: the Rasthof Formation of the Congo craton in northern Namibia and the Tsagaan Oloom Formation of the Dzabkhan terrane in Mongolia. The most abundant tests preserve morphological and compositional characters consistent with those found in at least two different families of modern lobose testate amoebae (Amoebozoa), a group of heterotrophic microbial eukaryotes. The presence of spatially and compositionally variable clay minerals, quartz and microcline on the test walls is a signature of widespread biological agglutination. The post-glacial fossil assemblages differ from the most common pre-Sturtian vase-shaped fossil testate amoebae, perhaps as a result of different preservational mechanisms or of the appearance of new forms after the glaciation."[281]

"Sturtian cap carbonates from Namibia and Mongolia contain many agglutinated tests."[281]

Fossils of testate amoeba (or Arcellinida) first appear during the Cryogenian period.[282]

During the Cryogenian period, the oldest known fossils of sponges, Otavia the first sponge-like animal[283] (and therefore animals) make an appearance.[284][285][286]

New groups of life evolved during this period, including the red algae and green algae, stramenopiles, ciliates, dinoflagellates, and testate amoeba.[287]

The end of the period also saw the origin of heterotrophic plankton, which would feed on unicellular algae and prokaryotes, ending the bacterial dominance of the oceans.[288]

Sturtian[edit | edit source]

The duration of the Sturtian glaciation has been variously defined, with dates ranging from 717 to 643 Ma.[289][290][291] Or, the period spans 715 to 680 Ma.[292]

Pre-Sturtian[edit | edit source]

The "Mariam Bohkahko Formation, coupled with the presence of substantial stromatolitic carbonate and beds of oncoids in sediments directly below the diamictite, suggests that conditions remained warm enough to sustain shallow-water carbonate production until just prior to the deposition of glacial diamictite."[293]

Oncolites are very similar to stromatolites, but, instead of forming columns, they form approximately spherical structures.[294] The oncoids often form around a central nucleus, such as a shell fragment,[295] and a calcium carbonate structure is deposited by encrusting microbes. Oncolites are indicators of warm waters in the photic zone, but are also known in contemporary freshwater environments.[296]

"Stromatolites [are] characteristic of the Matheos-Mariam Bohkahko Formation transition."[293]

"Oncolite [is] from the upper Mariam Bohkahko Formation 23 meters below the Negash Formation diamictite. Oncoids are up to 3 cm in diameter, and are cored by carbonate grains and shale rip-up clasts"[293]

Fossils of testate amoeba (or Arcellinida) first appear during the Cryogenian period.[297] During the Cryogenian period, the oldest known fossils of sponges (and therefore animals) formed.[298][299][300]

New groups of life evolved during this period, including the red algae and green algae, stramenopiles, ciliates, dinoflagellates, and testate amoeba.[301] The end of the period also saw the origin of heterotrophic plankton, which would feed on unicellular algae and prokaryotes, ending the bacterial dominance of the oceans.[302]

Vendian[edit | edit source]

The Vendian occurred about 740 Ma.

Paleontological substantiation of this boundary was worked out separately for the siliciclastic basin (base of the Baltic Stage of the Eastern European Platform[303]) and for the carbonate basin (base of the Tommotian Stage of the Siberian Platform).[304]

The lower boundary of the Vendian was suggested to be defined at the base of the Varanger (Laplandian) tillites.[305][306]

The Redkino, Kotlin and Rovno regional stages have been substantiated in the type area of the Vendian on the basis of the abundant organic-walled microfossils, megascopic algae, metazoan body fossils and ichnofossils.[305][307]

The lower boundary of the Vendian could have a biostratigraphic substantiation as well taking into consideration the worldwide occurrence of the Pertatataka assemblage of giant acanthomorph acritarchs.[306]

Beiyixi glaciaton[edit | edit source]

The Beiyixi is later than 755 Ma.

Tonian[edit | edit source]

The Tonian is the first geologic period of the Neoproterozoic Era, from 1000 to 720 Mya, defined by the International Commission on Stratigraphy (ICS) based on radiometric chronometry. The Tonian is preceded by the Stenian Period of the Mesoproterozoic era and followed by the Cryogenian.[308]

The Tonian spans 1000 to 850 Ma.[309][310]

Def. "a geologic period within the Neoproterozoic era from about 1000 to 850 million years ago"[311] is called the Tonian.

"Re-Os age constraints place the negative isotope excursion preceding the Sturtian glaciation (Islay anomaly) between 739 ± 6 Ma and 732 ± 4 Ma, that is, >15 m.y. before the first diamictites (Rooney et al., 2014; Strauss et al., 2014)."[293]

The "upper ~1 km of the Tambien Group [...] begins with the Didikama Formation—extensively dolomitized and recrystallized pale-brown carbonates interbedded with siltstones. This transitions into well-preserved limestone ribbonite (micrite with ribbon-like laminations) with molar tooth structures of the Matheos Formation. Carbonates near the contact between these two formations record a large negative 𝛅13
excursion to values below -6‰ that was tentatively correlated with the Islay anomaly (Swanson-Hysell et al., 2015) [...]. The ribbonites that record the recovery from the negative anomaly transition into the upper Matheos Formation, which is dominated by oolitic grainstones with abundant molar tooth structures. Dolomitized stromatolites and minor fine-grained siliciclastics serve as a distinctive and consistent marker for the base of the overlying Mariam Bohkahko Formation."[293]

"The Islay anomaly is a sharp negative 𝛅13
excursion with a nadir below -6‰ recognized to precede the Sturtian glaciation (Hoffman et al., 2012). The anomaly currently is bracketed stratigraphically by two Re-Os isochron ages of 732.2 ± 4.7 Ma and 739.9 ± 6.1 Ma (2V errors with all external uncertainties) from Laurentia (Rooney et al., 2014; Strauss et al., 2014). These constraints suggest that the Islay anomaly precedes the Sturtian glaciation by >15 m.y., which negates direct causative links between the 𝛅13
excursion and the initiation of Snowball Earth events (Hoffman et al., 1998; Schrag et al., 2002; Pavlov et al., 2003; Rothman et al., 2003; Tziperman et al., 2011)."[293]

"A couplet of crystal-rich tuffs, 4 and 8 cm thick, and separated by 7 cm, were collected as a single sample (T46–102_2Z) just above the contact between the Didikama and Matheos Formations. The tuffs are within the recovery from the Islay anomaly, as they are 2 m above 𝛅13
values of -4‰, and within carbonates with 𝛅13
values of ~0‰. Zircons separated from the sample were translucent and euhedral. Dates from these zircons were confined to between 738 and 735 Ma, indicating a lack of detrital zircon input. The weighted mean date for the sample, 735.25 ± 0.25/0.88 Ma (2V; without/with external uncertainties), is within uncertainty of the Re-Os isochron dates of 732.2 ± 4.7 Ma and 739.9 ± 6.1 Ma (2V; including external uncertainties) that are interpreted to bracket the Islay anomaly (Rooney et al., 2014; Strauss et al., 2014). Independent Re-Os and U-Pb age constraints now indicate that the deeply negative Islay isotope anomaly is globally synchronous and precedes the Sturtian glaciation by ~18 m.y. The integrated chemostratigraphy and geochronology now confirm that the Tambien basin uniquely records a prolonged 𝛅13
+5‰ plateau preserved in the Matheos and lower most Mariam Bohkahko Formations, followed by less positive values (~+2‰), prior to deposition of the first diamictites [...]."[293]

The first putative metazoans (animal) fossils dated to the late Tonian (ca 800 Mya), e.g. Otavia antiqua, which has been described as a sponge which is consistent with molecular data recovered through genetic studies on modern metazoan species; more recent studies have concluded that the base of the animal phylogenetic tree is in the Tonian.[312]

Karatau[edit | edit source]

The Karatau spans 1100 to 800 Ma.[310]

Stenian[edit | edit source]

The Stenian Period is the final geologic period in the Mesoproterozoic Era and lasted from 1200 Mya to 1000 Mya (million years ago) defined chronometrically. The name derives from narrow polymetamorphic belts formed over this period.

Fossils of the oldest known sexually reproducing organism, Bangiomorpha pubescens, a red alga,[313] first appeared in the Stenian.[314]

Ectasian[edit | edit source]

"The Ectasian [1,400-1,200 Ma] is the second period of the Mesoproterozoic Era, occuring after the Calymmian, and before the Stenian."[315]

"Acritarchs (unidentified organic-walled microfossils of possible fungal, algal or other origins) appear in the fossil record."[315]

Acritarchs were originally defined as non-acid soluble (i.e. non-carbonate, non-siliceous) organic-walled microfossils consisting of a central cavity, and whose biological affinities cannot be determined with certainty.[316][317][318]

It is likely that most acritarch species from the Paleozoic represent various stages of the life cycle of algae that were ancestral to the dinoflagellates.[319]

Calymmian[edit | edit source]

The Calymmian Period is the first geologic period in the Mesoproterozoic Era and lasted from 1600 Mya to 1400 Mya (million years ago), defined chronometrically.[320]

"During the Calymmian Period, oxygen built up above 10 % in the atmosphere and photosynthetic organisms grew rapidly. Eukaryotic cells appeared during this period, about 1,500 million years ago."[321]

Statherian[edit | edit source]

1.6 Ga Ramathallus fossil is the earliest known red alga. Credit: Stefan Bengtson, Therese Sallstedt, Veneta Belivanova, and Martin Whitehouse.{{free media}}

The Statherian Period is the final geologic period in the Paleoproterozoic Era and lasted from 1800 Mya to 1600 Mya (million years ago), defined chronometrically.[322][323]

Rafatazmia, controversially[324] claimed to be present in Statherian beds in India, may be the oldest known confirmably eukaryotic fossil organism.[325]

The diversification of crown group eukaryotic macroorganisms seems to have started about 1.6–1 Gya,[326] seemingly coinciding with an increase in key nutrient concentrations.[327] According to phylogenetic analysis, plants diverged from animals and fungi about 1.6 Gya; animals and fungi about 1.5 Gya; Bilaterians and cnidarians (animals respectively with and without bilateral symmetry) about 1.3 Gya; sponges 1.35 Gya;[328] and Ascomycota and Basidiomycota (the two divisions of the fungus subkingdom Dikarya) 0.97 Gya.[328] The earliest known red algae [Ramathallus] mats date to 1.6 Gya.[329] The earliest known fungus dates to 1.01–0.89 Gya from Northern Canada.[330] Multicellular eukaryotes, thought to be the descendants of colonial unicellular aggregates, had probably evolved about 2–1.4 Gya.[331][332] Likewise, early multicellular eukaryotes likely mainly aggregated into stromatolite mats.[333]

Orosirian[edit | edit source]

"Prokaryotic micro-fossils [occur] in the carbonaceous shale of Gwalior basin" dated to 2000 Ma (Orosirian Period).[334]

The Orosirian Period is the third geologic period in the Paleoproterozoic Era and lasted from 2050 Mya to 1800 Mya (million years ago).[335]

Rhyacian[edit | edit source]

Francevillian biota fossils are shown. Credit: Ventus55.{{free media}}
A member of the Francevillian biota has a maximum fossil diameter of 12 cm. Credit: Ventus55.{{free media}}

The Francevillian biota (also known as Gabon macrofossils or Gabonionta) is a group of 2.1-billion-year-old Palaeoproterozoic, macroscopic organisms known from fossils found in Gabon in the Palaeoproterozoic Francevillian B Formation, a black shale province. The fossils are postulated to be evidence of the earliest form of multicellular life.[336] While the fossils have yet to be assigned to a formal taxonomic position, they have been informally and collectively referred to as the "Gabonionta" by the Natural History Museum Vienna in 2014.[337]

The fossil organisms are up to 17 cm in size.[338][339] Their bodies were flattened disks with a characteristic morphology, including circular and elongated individuals and a spherical to ellipsoidal central body bounded by radial structures shows three-dimensionality and coordinated growth.[338] Cell-cell communication must be assumed as it existed before multi-cellularity arose.[340]

The Rhyacian Period is the second geologic period in the Paleoproterozoic Era and lasted from 2300 Mya to 2050 Mya Mya (million years ago),[341] defined chronometrically.[342]

Makganyene glaciation[edit | edit source]

"Cyanobacteria appear to have evolved in the short interval between the Huronian glaciations and the Makganyene glaciation."[343]

The "production of large quantities of free O2 was triggered by the evolution of oxygenic photosynthesis. We suggest the oldest strong geological evidence for O2 is the 2.22 Ga Kalahari Mn member of the Hotazel BIF (1), as in the oceans only free O2 can oxidize soluble Mn(II) into insoluble Mn(IV)."[343]

The "oxygenation event seems to correlate with the Makganyene glaciation, at 2.22 Ga (6). The appearance of red beds in the Upper Timeball Hill formation directly underlying the Makganyene diamictite supports this interpretation."[343]

Huronian ice age[edit | edit source]

Grypania spiralis fossil is shown. Credit: Xvazquez.

"The Gordon Lake Formation of the Paleoproterozoic Huronian Supergroup is a primarily- siliciclastic succession ranging from 300 to 1100 m thick. Lithostratigraphic and sedimentological analysis of the formation in the Bruce Mines and Flack Lake areas, and Killarney and Lady Evelyn-Smoothwater provincial parks revealed 7 lithofacies, which comprise 3 distinct lithofacies associations. The lithofacies associations are subtidal nearshore, subtidal to shallow shelf, and mixed intertidal flat. Microbially-induced sedimentary structures (MISS) related to microbial mat destruction and decay were recognized in the Flack Lake area. The preserved MISS include sand cracks, mat chips, remnant gas domes, and pyrite patches, and iron laminae. A biological origin for the fossil structures is supported by their similarities to modern and ancient documented examples of MISS, the sand-dominated nature of the substrate in which they are preserved, and key microtextures identified in thin section. The identified MISS support the interpretation of a tidal flat depositional environment."[344]

Grypania is an early, tube-shaped fossil from the Proterozoic eon, with a size over one centimeter and consistent form, could have been a giant bacterium, a bacterial colony, or a eukaryotic alga.[345] The oldest probable Grypania fossils date to about 2300 million years ago (redated from the previous 1870 million)[345][346] and the youngest extended into the Ediacaran period.[347]

Gowganda glaciation[edit | edit source]

Grypania spiralis fossil is shown. Credit: Xvazquez.

The Huronian Ice Age is known "mainly from Canada and the United States in North America, where dated rocks range from 2500 to 2100 million years old. The Gowgonda Formation of Ontario is especially noteworthy for its excellent preservation of glaciogenic strata dated about 2300 million years old. Other glacial deposits are found in Wyoming, Michigan, Quebec, and the Northwest Territories. These rocks record extensive Early Proterozoic continental glaciation through a time span of about 400 million years, during which three or more glacial expansions took place. The configuration of the continents during this time is highly speculative."[348]

Grypania is an early, tube-shaped fossil from the Proterozoic eon, with a size over one centimeter and consistent form, could have been a giant bacterium, a bacterial colony, or a eukaryotic alga.[345] The oldest probable Grypania fossils date to about 2300 million years ago (redated from the previous 1870 million)[345][349] and the youngest extended into the Ediacaran period.[347]

Bruce glaciation[edit | edit source]

"The second Huronian glaciation is represented by the Bruce diamictite and is correlated with the Vagner diamictite in the Snowy Pass Supergroup (Wyoming) [49]."[350]

"Sandstones and arkoses of the Mississagi Fm. are succeeded by the glacially derived Bruce Fm., which contains dropstones [26] and is immediately overlain by a carbonate with carbon isotope characteristics that broadly resemble those described for Neoproterozoic cap carbonates [17]. Sedimentary rocks of the post-glacial Espanola Fm. constitute a transition from a lower carbonate–limestone member to a higher siltstone-heterolithic member, which is interpreted to have formed in a shallow-marine or restricted lacustrine environment possibly during a period of active continental fragmentation [15,27–29]. Rare columnar stromatolite features have also been reported in the Espanola carbonate [30]."[350]

Ramsey Lake glaciation[edit | edit source]

"The glacial diamictite of the Ramsey Lake Formation [...] contains dropstones in siltstone interbeds, implies deposition in a glaciomarine setting at an ice margin."[350]

"A recent study of the organic geochemistry of the pre-glacial Matinenda Fm. has documented oil droplets with relatively high levels of 2α-methylhopanes and other biomarkers interpreted to be eukaryotic in origin [22]. It was also suggested that the oil probably migrated in the Matinenda Fm. from the McKim Fm. [which underlays the Ramsey Lake Formation] during post-depositional processes and consider unlikely the possibility that these cyanobacterial biomarkers are indigenous to the Matinenda Fm."[350]

Siderian[edit | edit source]

A Siderian banded iron formation shown in Dales Gorge, Western Australia. Credit: Graeme Churchard from Bristol, UK.{{free media}}

The Siderian Period, meaning "iron" period) is the first geologic period in the Paleoproterozoic Era and lasting from 2500 Ma to 2300 Ma (million years ago), based on dates defined chronometrically.

The deposition of banded iron formations, peaking early in this period, were formed as anaerobic cyanobacteria produced waste oxygen that combined with iron, forming magnetite (Fe3O4, an iron oxide), removing iron from the Earth's oceans, presumably turning greenish seas clear, with no remaining iron in the oceans to serve as an oxygen sink, the process allowed the buildup of an oxygen-rich atmosphere, with the second, follow-on event known as the oxygen catastrophe, possibly triggering the Huronian glaciation.[351][352]

Neoarchean[edit | edit source]

Def. "a geologic era within the Archaean eon from about 2800 to 2500 million years ago"[353] or the "era from 2,800 Ma to 2,500 Ma"[354] is called a Neoarchean.

Biomarkers of cyanobacteria discovered c. 2,700 Ma, together with steranes (sterols of cholesterol), associated with films of eukaryotes, in shales located beneath banded iron formation hematite beds, in Hamersley Range, Western Australia;[355] skewed sulfur isotope ratios found in pyrites show a small rise in oxygen concentration in the atmosphere;[356] Sturgeon Lake Caldera forms in Wabigoon greenstone belt – contains well preserved homoclinal chain of greenschist facies, metamorphosed intrusive, volcanic and sedimentary layers (Mattabi pyroclastic flow considered third most voluminous eruptive event); stromatolites of Bulawayo series in Zimbabwe form – first verified reef community on Earth.

Mesoarchean[edit | edit source]

Def. "a geologic era within the Archaean eon from about 3200 to 2800 million years ago; stromatolites have existed from this time"[357] or the "era from 3,200 Ma to 2,800 Ma"[357] is called the Mesoarchean.

The earliest reefs date from this era, and were probably formed by stromatolites.[358][359]

Paleoarchean[edit | edit source]

A stromatolite formed by Paleoarchean microbial mats is preserved as a fossil, from Pilbara craton, Western Australia. Credit: Didier Descouens.

Def. "a geologic era within the Archaean eon from about 3600 to 3200 million years ago; the first aerobic bacteria appeared at this time"[360] or the "era from 3,600 Ma to 3,200 Ma"[360] is called the Paleoarchean.

The earliest known life forms on Earth are putative fossilized microorganisms found in hydrothermal vent precipitates, considered to be about 3.42 billion years old.[361][362]

The earliest direct evidence of life on Earth are microfossils of microorganisms permineralized in 3.465-billion-year-old Australian Apex chert rocks.[363][364]

Eoarchean[edit | edit source]

Def. "a geologic era within the Archaean eon from about 4600 to 3600 million years ago; the first single-celled life began at this time"[365] or the "era from 4,000 Ma to 3,600 Ma"[366] is called the Eoarchean.

"Some graphite contained in the 3.7-billion-year-old metasedimentary rocks of the Isua Supracrustal Belt, Western Greenland1, is depleted in 13
and has been interpreted as evidence for early life2. However, it is unclear whether this graphite is primary, or was precipitated from metamorphic or igneous fluids3,4. Here we analyse the geochemistry and structure of the 13
-depleted graphite in the Isua schists. Raman spectroscopy and geochemical analyses indicate that the schists are formed from clastic marine sediments that contained 13
-depleted carbon at the time of their deposition. Transmission electron microscope observations show that graphite in the schist occurs as nanoscale polygonal and tube-like grains, in contrast to abiotic graphite in carbonate veins that exhibits a flaky morphology. Furthermore, the graphite grains in the schist contain distorted crystal structures and disordered stacking of sheets of graphene. The observed morphologies are consistent with pyrolysation and pressurization of structurally heterogeneous organic compounds during metamorphism. We thus conclude that the graphite contained in the Isua metasediments represents traces of early life that flourished in the oceans at least 3.7 billion years ago."[367] And, possible stromatolites[368][369][370] were discovered in 3.7 billion-year-old metasedimentary rocks in southwestern Greenland.

The earliest time that life forms first appeared on Earth is at least 3.77 billion years ago.[362] Possibly they existed as early as 4.28 billion years.[362]

In 2008, another rock formation was discovered in the Nuvvuagittuq greenstone belt in northern Québec, Canada which has been dated to be 4,280 million years ago.[371]

Hadean[edit | edit source]

Aerial photo of Jack Hill, Australia, indicates the Hadean portion. Credit: Robert Simmon, NASA.{{free media}}
Evidence of possibly the oldest forms of life on Earth has been found in hydrothermal vent precipitates.[361][362][372] Credit: NOAA.{{free media}}

Def. "the geologic eon from about 4,600 to 3,800 million years ago; marked by the formation of the solar system, a stable Earth-Moon orbit and the first rocks"[373] or the "eon before 4,000 Ma"[373] is called the Hadean.

Potential "biotic material, remains of life" were found in 4.1 billion-year-old rocks in Western Australia and described in a 2015 study.[374]

In March 2017, fossilized microorganisms (microfossils) were announced to have been discovered in hydrothermal vent precipitates from an ancient sea-bed in the Nuvvuagittuq Greenstone Belt of Quebec, Canada. These may be as old as 4.28 billion years, the oldest evidence of life on Earth, suggesting "an almost instantaneous emergence of life" after ocean formation 4.41 billion years ago.[362][372][375][376]

The earliest time that life forms first appeared on Earth is even 4.41 billion years[377][378]—not long after the oceans formed 4.5 billion years ago, and after the formation of the Earth 4.54 billion years ago.[362][372][375][376]

Hypotheses[edit | edit source]

  1. To obtain index fossils in locations where exposures do not occur, corings may provide alternatives.

See also[edit | edit source]

References[edit | edit source]

  1. SemperBlotto (28 February 2005). "paleontology". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2012-07-22. {{cite web}}: |author= has generic name (help)
  2. Stephen Jay Gould; Norman L. Gilinsky; Rebecca Z. German (June 1987). "Asymmetry of lineages and the direction of evolutionary time". Science 236 (4807): 1437-41. doi:10.1126/science.236.4807.1437. Retrieved 2011-08-02. 
  3. Dvortygirl (1 May 2005). "fossil". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2012-07-22. {{cite web}}: |author= has generic name (help)
  4. EncycloPetey (5 May 2009). "fossil". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2012-07-22. {{cite web}}: |author= has generic name (help)
  5. EncycloPetey (18 June 2009). "fossil". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2012-07-22. {{cite web}}: |author= has generic name (help)
  6. Tooironic (27 March 2011). "fossil". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2012-07-22. {{cite web}}: |author= has generic name (help)
  7. SemperBlotto (25 February 2006). "index fossil". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 23 September 2021. {{cite web}}: |author= has generic name (help)
  8. "International Commission on Stratigraphy 2008". Retrieved 9 March 2009.
  9. 9.0 9.1 9.2 Christopher T. Fisher; Helen P. Pollard; Isabel Israde-Alcántara; Victor H. Garduño-Monroy; Subir K. Banerjee (April 2003). "A reexamination of human-induced environmental change within the Lake Pátzcuaro Basin, Michoacán, Mexico". Proceedings of the National Academy of Sciences USA 100 (8): 4957-4962. doi:10.1073/pnas.0630493100. Retrieved 2018-2-25. 
  10. 10.0 10.1 10.2 10.3 10.4 10.5 10.6 J.N. Lanting (2015). "DATES FOR ORIGIN AND DIFFUSION OF THE EUROPEAN LOGBOAT". Palaeohistoria 57: 627-650. Retrieved 2017-10-13. 
  11. P. E. Damon, D. J. Donahue, B. H. Gore, A. L. Hatheway, A. J. T. Jull, T. W. Linick, P. J. Sercel, L. J. Toolin, C. R. Bronk, E. T. Hall, R. E. M. Hedges, R. Housley, I. A. Law, C. Perry, G. Bonani, S. Trumbore, W. Woelfli, J. C. Ambers, S. G. E. Bowman, M. N. Leese, M. S. Tite (1989). "Radiocarbon dating of the Shroud of Turin". Nature 337 (6208): 611–5. doi:10.1038/337611a0. 
  12. William Meacham (June 1983). "The Authentication of the Turin Shroud: An Issue in Archaeological Epistemology". Current Anthropology 24 (3): 283-311. Retrieved 2017-10-10. 
  13. 13.0 13.1 13.2 Dela (17 December 2002). Skaramissalet daterat till 1150. Swedish radio. Retrieved 2017-10-10. 
  14. Janet M. Wilmshurst, Terry L. Hunt, Carl P. Lipo, and Atholl J. Anderson (1 February 2011). "High-precision radiocarbon dating shows recent and rapid initial human colonization of East Polynesia". Proceedings of the National Academy of Sciences USA 108 (5): 1815-1820. doi:10.1073/pnas.1015876108. Retrieved 2017-10-10. 
  15. G. Skoglund, M. Nockert & B. Holst (2013). "Viking and Early Middle Ages Northern Scandinavian Textiles Proven to be made with Hemp". Nature Scientific Reports 3: 2686. doi:10.1038/srep02686. Retrieved 2017-10-10. 
  16. Sophie Berthier (1997). Recherches archéologiques sur la capitale de l'empire de Ghana: Etude d'un secteur, d'habitat à Koumbi Saleh, Mauritanie: Campagnes II-III-IV-V (1975–1976)-(1980–1981), In: Cambridge Monographs in African Archaeology 41. British Archaeological Reports 680. Oxford: Archaeopress. pp. 143. ISBN 0-86054-868-6. Retrieved 2017-10-10. 
  18. T. Millat (1982). Essex Archaeology and History. Mersea, UK: Mersea Museum. Retrieved 2017-06-21. 
  20. A. Speranza; J. van der Plicht; B. van Geel (November 2000). "Improving the time control of the Subboreal/Subatlantic transition in a Czech peat sequence by 14C wiggle-matching". Quaternary Science Reviews 19 (16): 1589-1604. doi:10.1016/S0277-3791(99)00108-0. Retrieved 2014-11-04. 
  21. Christopher Bronk Ramsey; Michael W. Dee; Joanne M. Rowland; Thomas F. G. Higham; Stephen A. Harris; Fiona Brock; Anita Quiles; Eva M. Wild et al. (18 June 2010). "Radiocarbon-Based Chronology for Dynastic Egypt". Science 328 (5985): 1554-1557. doi:10.1126/science.1189395. Retrieved 2017-10-11. 
  22. Hendrik Bruins; Johannes van der Plicht (1995). "Tell-es-Sultan (Jericho): Radiocarbon results of short-lived cereal and multiyear charcoal samples from the end of the Middle Bronze Age". Radiocarbon 37 (2): 213-220. Retrieved 2017-10-11. 
  23. E.B. Karabanov; A.A. Prokopenko; D.F. Williams; G.K. Khursevich (March 2000). "A new record of Holocene climate change from the bottom sediments of Lake Baikal". Palaeogeography, Palaeoclimatology, Palaeoecology 156 (3-4): 211–24. doi:10.1016/S0031-0182(99)00141-8. Retrieved 2014-11-04. 
  24. Botteville (19 February 2006). Atlantic (period). San Francisco, California: Wikimedia Foundation, Inc. Retrieved 15 July 2018. 
  25. 25.0 25.1 Willi Dansgaard (2005). The Department of Geophysics of The Niels Bohr Institute for Astronomy Physics and Geophysics at The University of Copenhagen Denmark. ed. Frozen Annals Greenland Ice Cap Research. Copenhagen, Denmark: Niels Bohr Institute. pp. 123. ISBN 87-990078-0-0. Retrieved 2014-10-05. 
  26. 26.0 26.1 26.2 26.3 Bernd Kromer; Bernd Becker (1993). "German Oak and Pine 14C Calibration, 7200-9439 BC". Radiocarbon 35 (1): 125-135. Retrieved 2017-10-13. 
  27. 27.0 27.1 J. W. Franks; W. Pennington (April 1961). "The Late-Glacial and Post-Glacial Deposits of the Esthwaite Basin, North Lancashire". New Phytologist 60 (1): 27-42.;jsessionid=EB6966DF0A2FBCC3534CCD6A6413808D.f02t01?v=1&t=i23es9k1&s=e619673cf5bc8be51450a303a914df03f8cba94d. Retrieved 2014-11-04. 
  28. 28.0 28.1 James Hansford; Patricia C. Wright; Armand Rasoamiaramanana; Ventura R. Pérez; Laurie R. Godfrey; David Errickson; Tim Thompson; Samuel T. Turvey (12 September 2018). "Early Holocene human presence in Madagascar evidenced by exploitation of avian megafauna". Sciences Advances 4 (9): eaat6925. Retrieved 19 September 2018. 
  29. 29.0 29.1 Jan Mangerud (1987). W. H. Berger. ed. The Alleröd/Younger Dryas Boundary, In: Abrupt Climatic Change. D. Reidel Publishing Company. pp. 163-71.,YD%20boundary.PDF. Retrieved 2014-11-03. 
  30. Bronowski, Jacob (1973). The Ascent of Man. London: BBC. ISBN 978-1-849-90115-4. 
  31. Teeple, John B. (2002). Timelines of World History. London: Dorling Kindersley Ltd. ISBN 0-75133-742-0. 
  32. Teeple, John B. (2002). Timelines of World History. London: Dorling Kindersley Ltd. ISBN 0-75133-742-0. 
  33. Teeple, John B. (2002). Timelines of World History. London: Dorling Kindersley Ltd. ISBN 0-75133-742-0. 
  34. David Whitehouse (9 August 2000). "Ice Age star map discovered – thought to date back 16,500 years". BBC News. BBC. Retrieved 18 November 2019.
  35. "Lascaux Cave". Ancient-Wisdom. 2019. Retrieved 18 November 2019.
  36. "History of the Magdalenian". The Magdalenian. Les Eyzies. 2019. Retrieved 18 November 2019.
  37. 37.0 37.1 Evan K. Irving-Pease (2018). "Palaeogenomics of Animal Domestication". In Lindqvist, C.; Rajora, O.. Palaeogenomics. Population Genomics. Springer, Cham. pp. 225–272. doi:10.1007/13836_2018_55. ISBN 978-3-030-04752-8. 
  38. Olaf Thalmann; Angela R. Perri (2018). "Palaeogenomic Inferences of Dog Domestication". In Lindqvist, C.; Rajora, O.. Palaeogenomics. Population Genomics. Springer, Cham. pp. 273–306. doi:10.1007/13836_2018_27. ISBN 978-3-030-04752-8. 
  39. David E. Machugh (2016). "Taming the Past: Ancient DNA and the Study of Animal Domestication". Annual Review of Animal Biosciences 5: 329–351. doi:10.1146/annurev-animal-022516-022747. PMID 27813680. 
  40. C. A. Driscoll (2007). "The Near Eastern Origin of Cat Domestication". Science 317 (5837): 519–523. doi:10.1126/science.1139518. ISSN 0036-8075. PMID 17600185. PMC 5612713. // 
  41. Dowd, Marion (2016). "A Remarkable Cave Discovery". Archaeology Ireland 30 (2): 21–25. 
  42. Fujita, Masaki (2016). "Advanced maritime adaptation in the western Pacific coastal region extends back to 35,000–30,000 years before present". Proceedings of the National Academy of Sciences of the United States of America 113 (40): 11184–11189. doi:10.1073/pnas.1607857113. PMID 27638208. 
  43. Winter, Barbara. "Bering Land Bridge". SFU Museum of Archaeology and Ethnology. Retrieved 2 March 2019.
  44. Teeple, John B. (2002). Timelines of World History. London: Dorling Kindersley Ltd. ISBN 0-75133-742-0. 
  45. A. E. Sanders, R. E. Weems & L. B. Albright III (2009). Formalization of the mid-Pleistocene "Ten Mile Hill beds" in South Carolina with evidence for placement of the Irvingtonian-Rancholabrean boundary. Museum of Northern Arizona Bulletin (64:369-375).
  46. D. E. Savage (1951). Late Cenozoic vertebrates of the San Francisco Bay region. University of California Publications; Bulletin of the Department of Geological Sciences (28:215-314).
  47. Bell, C. J. (2004). "The Blancan, Irvingtonian, and Rancholabrean mammal ages". In Woodburne, M. O.. Late Cretaceous and Cenozoic Mammals of North America: Biostratigraphy and Geochronology. New York: Columbia University Press. pp. 232–314. ISBN 0-231-13040-6. 
  48. Michael R. Waters; Thomas W. Stafford Jr.; Brian Kooyman; L. V. Hills (23 March 2015). "Late Pleistocene horse and camel hunting at the southern margin of the ice-free corridor: Reassessing the age of Wally's Beach, Canada". PNAS 112 (14): 4263–4267. doi:10.1073/pnas.1420650112. PMID 25831543. PMC 4394292. // 
  49. Teeple, John B. (2002). Timelines of World History. London: Dorling Kindersley Ltd. ISBN 0-75133-742-0. 
  50. 50.0 50.1 50.2 Walter Alves Neves; André Prous; Rolando González-José; Renato Kipnis; Joseph Powell (2003). ""Early Holocene human skeletal remains from Santana do Riacho, Brazil: implications for the settlement of the New World". Journal of Human Evolution 45: 19-42. doi:10.1016/S0047-2484(03)00081-2. Retrieved 2015-07-23. 
  51. Joel D. Irish; Jacek Kabacinski; Czekaj-Zastawny Agnieszka (1 August 2019). "Who were the mysterious Neolithic people that enabled the rise of ancient Egypt? Here's what we've learned on our digs". The Conversation. Retrieved 2 August 2019.
  52. Hsain Ilahiane (17 July 2006). Historical Dictionary of the Berbers (Imazighen). Lanham, Maryland USA: The Scarecrow Press. pp. 360. ISBN 0810864908. Retrieved 22 September 2017. 
  53. Angelika Frantz; translated by Anne-Marie de Grazia (16 June 2013). "A Stone Ax from Doggerland, In: Der Spiegel". Retrieved 2017-02-07.
  54. 54.0 54.1 54.2 Konrad A. Hughes; Jonathan T. Overpeck; Larry C. Peterson; Susan Trumbore (7 March 1996). Rapid climate changes in the tropical Atlantic region during the last deglaciation. 380. pp. 51-4. Retrieved 2014-11-05. 
  55. Zicheng Yu; Ulrich Eicher (2001). "Three Amphi-Atlantic Century-Scale Cold Events during the Bølling-Allerød Warm Period". Géographie physique et Quaternaire 55 (2): 171-9. doi:10.7202/008301ar. Retrieved 2014-11-04. 
  56. Robert Lindsay (1 April 2017). An Ancient Link Between India and Australia. WordPress. Retrieved 2017-05-29. 
  57. Robert Lindsay (16 January 2017). The Chukchi – A Glimpse into An Ancient Past?. WordPress. Retrieved 2017-05-29. 
  58. Helen Thompson (21 July 2015). A DNA Search for the First Americans Links Amazon Groups to Indigenous Australians. Smithsonian Institution. Retrieved 2015-07-22. 
  59. J. Vandenberghe; G. Nugteren (2001). "Rapid climatic changes recorded in loess successions". Global and Planetary Change 28 (1-9): 222-30. Retrieved 2014-11-06. 
  60. A.A. Nikonov; M.M. Shakhnovich; J. van der Plicht (2011). "Age of Mammoth Remains from the Submoraine Sediments of the Kola Peninsula and Karelia". Doklady Earth Sciences 436 (2): 308-10. Retrieved 2014-11-06. 
  61. Donoghue, J (2006). "The Lynford mammoths: slaughtered by Neanderthals?". Current Archaeology (205): 40-44. 
  62. Boismier, B. (2002). "Lynford Quarry, A Neanderthal butchery site". Current Archaeology 16 (182): 53-58. 
  63. ROCEEH (1 July 2010). File:Motm 2010 07 Howiesons Poort.pdf. Wikimedia. Retrieved 11 July 2018. 
  64. 64.0 64.1 Hornyak, Tim (30 January 2020). "Japan Puts Its Mark on Geologic Time with the Chibanian Age". Eos – Earth & Space Science News. American Geophysical Union. Retrieved 31 January 2020.
  65. Cohen, K. M.; Finney, S. C.; Gibbard, P. L.; Fan, J.-X. (January 2020). "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. Retrieved 23 February 2020.
  66. Gradstein, Felix M.; Ogg, James G.; Smith, Alan G., eds (2004). A Geological Time Scale 2004 (3rd ed.). Cambridge: Cambridge University Press. p. 28. ISBN 9780521786737. 
  67. D. Dahl-Jensen & others (2013). "Eemian interglacial reconstructed from a Greenland folded ice core". Nature 493 (7433): 489–494. doi:10.1038/nature11789. PMID 23344358. 
  68. P. L. Gibbard (2015). "The Quaternary System/Period and its major subdivisions". Russian Geology and Geophysics 56 (4): 686–688. doi:10.1016/j.rgg.2015.03.015. 
  69. "Japan-based name 'Chibanian' set to represent geologic age of last magnetic shift". The Japan Times. 14 November 2017. Retrieved 13 November 2019.
  70. D. Richter & others (8 June 2017). "The Age of Hominin Fossils from Jebel Irhoud, Morocco, and the origins of the Middle Stone Age". Nature 546 (7657): 293–296. doi:10.1038/nature22335. PMID 28593967. .
  71. Crew, Bec (15 March 2016). "The Oldest Human Genome Ever Has Been Sequenced, And It Could Rewrite Our History". ScienceAlert. Retrieved 5 June 2019.
  72. 72.0 72.1 Sam L. VanLandingham (May 2010). "Use of diatoms in determining age and paleoenvironment of the Valsequillo (Hueyatiaco) early man site, Puebla, Mexsico, with corroboration by Chrysophyta cysts for a maximum Yarmouthian (430,000-500,00yr BP) age of the artifacts". Nova Hedwigia 136: 127-38. Retrieved 2017-06-16. 
  73. Carl Zimmer (7 June 2017). "Oldest Fossils of Homo Sapiens Found in Morocco, Altering History of Our Species". New York Times. Retrieved 2017-06-09.
  74. Philipp Gunz (7 June 2017). "Oldest Fossils of Homo Sapiens Found in Morocco, Altering History of Our Species". New York Times. Retrieved 2017-06-09.
  75. Chris Stringer (January 30, 2019). "Denisovans and Neanderthals likely overlapped at this Stone Age hot spot for thousands of years, and modern Homo sapiens may have dwelled there, too". The Scientist. Retrieved 31 January 2019.
  76. Chris Widga; Tara L. Fulton; Larry D. Martin; Beth Shapiro (October 2012). "Homotherium serum and Cervalces from the Great Lakes Region, USA: geochronology, morphology and ancient DNA". Boreas 41 (4): 547-56. doi:1111/j.1502-3885.2012.00267.x. Retrieved 2015-01-20. 
  77. Maria Bianca Cita; Philip L. Gibbard; Martin J. Head; the ICS Subcommission on Quaternary Stratigraphy (September 2012). "Formal ratification of the GSSP for the base of the Calabrian Stage (second stage of the Pleistocene Series, Quaternary System)". Episodes 35 (3): 388-97. Retrieved 2015-01-18. 
  78. John A. Van Couvering; Davide Castradori; Maria Bianca Cita; Frederik J. Hilgen; Domenico Rio (September 2000). [ "The base of the Zanclean Stage and of the Pliocene Series"]. Episodes 23 (3): 179-87. Retrieved 2015-01-23. 
  79. F.J. Hilgen; S. Iaccarino; W. Krijgsman; G. Villa; C.G. Langereis (2000). "The Global Boundary Stratotype Section and Point (GSSP) of the Messinian Stage (uppermost Miocene)". Episodes 23 (3): 172-178. Retrieved 2017-08-20. 
  80. 80.0 80.1 Christmas, Jane (2005-11-07). "Giant Ape lived alongside humans". McMaster University. Archived from the original on 2012-02-06. Retrieved 2007-12-06.
  81. Ciochon, R. (1996). "Dated Co-Occurrence of Homo erectus and Gigantopithecus from Tham Khuyen Cave, Vietnam" (PDF). Proceedings of the National Academy of Sciences of the United States of America 93 (7): 3016–3020. doi:10.1073/pnas.93.7.3016. PMID 8610161. PMC 39753. Retrieved 2007-12-06. 
  82. Sofwan, N. (2016). "Primata Besar di Jawa: Spesimen Baru Gigantopithecus dari Semedo/Giant Primate of Java: A new Gigantopithecus specimen from Semedo." (PDF). Berkala Arkeologi 36 (2): 141–160. Retrieved 2017-12-06. 
  83. Ciochon, R. (1991). "The ape that was – Asian fossils reveal humanity's giant cousin". Natural History 100: 54–62. ISSN 0028-0712. Archived from the original on May 25, 2015. Retrieved 2007-12-06. 
  84. Pettifor, Eric (2000) [1995]. "From the Teeth of the Dragon: Gigantopithecus blacki". Selected Readings in Physical Anthropology. Kendall/Hunt Publishing Company. pp. 143–149. ISBN 0-7872-7155-1. Retrieved 2008-01-30. 
  85. de Vos, J., 1993. Een portret van Pleistocene zoogdieren: Op zoek naar de reuzenaap (Gigantopithecus) in Vietnam. Cranium, 10(2), pp.123-127.
  86. Relethford, J. (2003). The Human Species: An Introduction to Biological Anthropology. McGraw-Hill. ISBN 978-0-7674-3022-7. 
  87. Dennel, R. (2009). The Palaeolithic Settlement of Asia. Cambridge University Press. ISBN 978-0-521-84866-4. 
  88. Singh, R. P.; Islam, Z. (2012). Environmental Studies. Concept Publishing Company Pvt. Ltd.. ISBN 978-81-8069-774-6. 
  89. Zhang, Y. and Harrison, T., 2017. Gigantopithecus blacki: a giant ape from the Pleistocene of Asia revisited. American journal of physical anthropology, 162(S63), pp.153-177. doi: 10.1002/ajpa.23150.
  90. 90.0 90.1 90.2 90.3 90.4 Felix M. Gradstein; Frits P. Agterberg; James G. Ogg; Jan Hardenbol; Paul Van Veen; Jacques Thierry; Zehui Huang (1995). A Triassic, Jurassic and Cretaceous Time Scale, In: Geochronology Time Scales and Global Stratigraphic Correlation. SEPM Special Publication No. 54. Society for Sedimentary Geology. doi:1-56576-024-7. Retrieved 2016-10-24. 
  91. <>
  92. 92.0 92.1 92.2 92.3 92.4 92.5 GeoWhen (2007)
  93. 93.0 93.1 Palaeos (2003)
  94. Robert A. Rohde (18 January 2005). Paleogene Period. GeoWhen Database. Retrieved 2015-09-16. 
  95. Steininger, Fritz F.; Aubry, M.P.; Berggren, W.A.; Biolzi, M.; M.Borsetti, A.; Cartlidge, Julie E.; Cati, F.; Corfield, R. et al. (1 March 1997). "The Global Stratotype Section and Point (GSSP) for the base of the Neogene". Episodes 20 (1): 23–28. doi:10.18814/epiiugs/1997/v20i1/005. 
  96. Haines, Tim; Walking with Beasts: A Prehistoric Safari, (New York: Dorling Kindersley Publishing, Inc., 1999)
  97. Silva, Isabella; Jenkins, D. (September 1993). "Decision on the Eocene-Oligocene boundary stratotype". Episodes 16: 379-382. Retrieved 13 December 2020. 
  98. Coccioni, Rodolfo; Montanari, Alessandro; Nice, David; Brinkhuis, Henk; Deino, Alain; Frontalini, Fabrizio; Liter, Fabrizio; Maiorano, Patricia et al. (1 March 2018). "The Global Stratotype Section and Point (GSSP) for the base of the Chattian stage (Paleogene System, Oligocene Series) at Monte Cagnero, Italy". Episodes 41 (1): 17–32. doi:10.18814/epiiugs/2018/v41i1/018003. Retrieved 29 August 2020. 
  99. O’Brien, Charlotte L.; Huber, Matthew; Thomas, Ellen; Pagani, Mark; Super, James R.; Elder, Leanne E.; Hull, Pincelli M. (13 October 2020). "The enigma of Oligocene climate and global surface temperature evolution". Proceedings of the National Academy of Sciences. 117 (41): 25302–25309. doi:10.1073/pnas.2003914117.
  100. Pekar, Stephen F.; DeConto, Robert M.; Harwood, David M. (February 2006). "Resolving a late Oligocene conundrum: Deep-sea warming and Antarctic glaciation". Palaeogeography, Palaeoclimatology, Palaeoecology 231 (1-2): 29–40. doi:10.1016/j.palaeo.2005.07.024. 
  101. Hauptvogel, D. W.; Pekar, S. F.; Pincay, V. (April 2017). "Evidence for a heavily glaciated Antarctica during the late Oligocene “warming” (27.8-24.5 Ma): Stable isotope records from ODP Site 690: LATE OLIGOCENE STABLE ISOTOPE RECORD". Paleoceanography 32 (4): 384–396. doi:10.1002/2016PA002972. 
  102. Wu, Fuli; Miao, Yunfa; Meng, Qingquan; Fang, Xiaomin; Sun, Jimin (January 2019). "Late Oligocene Tibetan Plateau Warming and Humidity: Evidence From a Sporopollen Record". Geochemistry, Geophysics, Geosystems 20 (1): 434–441. doi:10.1029/2018GC007775. 
  103. Denk, Thomas; Grímsson, Friðgeir; Zetter, Reinhard; Símonarson, Leifur A. (2011). "The Biogeographic History of Iceland – The North Atlantic Land Bridge Revisited". Late Cainozoic Floras of Iceland 35: 647–668. doi:10.1007/978-94-007-0372-8_12. 
  104. Rousse, Stephane; Duringer, Philippe; Stapf, Karl R. G. (July 2012). "An exceptional rocky shore preserved during Oligocene (Late Rupelian) transgression in the Upper Rhine Graben (Mainz Basin, Germany): OLIGOCENE ROCKY SHORE". Geological Journal 47 (4): 388–408. doi:10.1002/gj.1349. 
  105. Filek, Thomas; Hofmayer, Felix; Feichtinger, Iris; Berning, Björn; Pollerspöck, Jürgen; Zwicker, Jennifer; Smrzka, Daniel; Peckmann, Jörn et al. (July 2021). "Environmental conditions during the late Oligocene transgression in the North Alpine Foreland Basin (Eferding Formation, Egerian) – A multidisciplinary approach". Palaeogeography, Palaeoclimatology, Palaeoecology: 110527. doi:10.1016/j.palaeo.2021.110527. 
  106. Berggren, William A.; Prothero, Donald R. (1992). "Eocene-Oligocene climatic and biotic evolution: an overview". Eocene-Oligocene Climatic and Biotic Evolution. Princeton University Press. doi:10.1515/9781400862924.1. 
  107. Coxall, H.K.; Pearson, P.N. (2007). "The Eocene–Oligocene Transition". Deep-Time Perspectives on Climate Change: Marrying the Signal from Computer Models and Biological Proxies. The Micropalaeontological Society, Special Publications. London: The Geological Society. pp. 351–387. 
  108. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  109. Katz, Miriam E.; Miller, Kenneth G.; Wright, James D.; Wade, Bridget S.; Browning, James V.; Cramer, Benjamin S.; Rosenthal, Yair (May 2008). "Stepwise transition from the Eocene greenhouse to the Oligocene icehouse". Nature Geoscience 1 (5): 329–334. doi:10.1038/ngeo179. 
  110. Miller, K. G.; Browning, J. V.; Aubry, M.-P.; Wade, B. S.; Katz, M. E.; Kulpecz, A. A.; Wright, J. D. (1 January 2008). "Eocene-Oligocene global climate and sea-level changes: St. Stephens Quarry, Alabama". Geological Society of America Bulletin 120 (1-2): 34–53. doi:10.1130/B26105.1. 
  111. Dupont-Nivet, Guillaume; Krijgsman, Wout; Langereis, Cor G.; Abels, Hemmo A.; Dai, Shuang; Fang, Xiaomin (February 2007). "Tibetan plateau aridification linked to global cooling at the Eocene–Oligocene transition". Nature 445 (7128): 635–638. doi:10.1038/nature05516. 
  112. Eldrett, James S.; Greenwood, David R.; Harding, Ian C.; Huber, Matthew (June 2009). "Increased seasonality through the Eocene to Oligocene transition in northern high latitudes". Nature 459 (7249): 969–973. doi:10.1038/nature08069. 
  113. Davies, Richard; Cartwright, Joseph; Pike, Jennifer; Line, Charles (April 2001). "Early Oligocene initiation of North Atlantic Deep Water formation". Nature 410 (6831): 917–920. doi:10.1038/35073551. 
  114. Torsvik, Trond H.; Cocks, L. Robin M. (2017). Earth history and palaeogeography. Cambridge, United Kingdom: Cambridge University Press. pp. 241–245. ISBN 9781107105324.
  115. Christin, Pascal-Antoine; Besnard, Guillaume; Samaritani, Emanuela; Duvall, Melvin R.; Hodkinson, Trevor R.; Savolainen, Vincent; Salamin, Nicolas (January 2008). "Oligocene CO2 Decline Promoted C4 Photosynthesis in Grasses". Current Biology 18 (1): 37–43. doi:10.1016/j.cub.2007.11.058. 
  116. Sage RF (July 2016). "A portrait of the C4 photosynthetic family on the 50th anniversary of its discovery: species number, evolutionary lineages, and Hall of Fame". Journal of Experimental Botany 67 (14): 4039–56. doi:10.1093/jxb/erw156. PMID 27053721. 
  117. Torsvik, Trond H.; Cocks, L. Robin M. (2017). Earth history and palaeogeography. Cambridge, United Kingdom: Cambridge University Press. pp. 241–245. ISBN 9781107105324.
  118. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  119. Retallack, G.J. (1983). "Late Eocene and Oligocene paleosols from Badlands National Park, South Dakota". Geological Society of America Special Paper 193. ISBN 9780813721934. 
  120. Méndez-Cárdenas, Juliana P.; Cevallos-Ferriz, Sergio R.S.; Calvillo-Canadell, Laura; Rodríguez-Yam, Gabriel A.; Borja, Amparo M.; Martínez-Cabrera, Hugo I. (August 2014). "Loxopterygium wood in Coayuca de Andrade, Oligocene of Puebla, Mexico". Review of Palaeobotany and Palynology 207: 38–43. doi:10.1016/j.revpalbo.2014.04.004. 
  121. Buerki, Sven; Forest, Félix; Stadler, Tanja; Alvarez, Nadir (July 2013). "The abrupt climate change at the Eocene–Oligocene boundary and the emergence of South-East Asia triggered the spread of sapindaceous lineages". Annals of Botany 112 (1): 151–160. doi:10.1093/aob/mct106. 
  122. Denk, Thomas; Grimm, Guido W. (December 2009). "The biogeographic history of beech trees". Review of Palaeobotany and Palynology 158 (1-2): 83–100. doi:10.1016/j.revpalbo.2009.08.007. 
  123. Torsvik & Cocks 2017, p. 254.
  124. Herendeen, Patrick S.; Dilcher, David L. (March 1990). "Fossil mimosoid legumes from the Eocene and Oligocene of southeastern North America". Review of Palaeobotany and Palynology 62 (3-4): 339–361. doi:10.1016/0034-6667(90)90094-Y. 
  125. Escudero, Marcial; Hipp, Andrew L.; Waterway, Marcia J.; Valente, Luis M. (June 2012). "Diversification rates and chromosome evolution in the most diverse angiosperm genus of the temperate zone (Carex, Cyperaceae)". Molecular Phylogenetics and Evolution 63 (3): 650–655. doi:10.1016/j.ympev.2012.02.005. 
  126. Devore, M.L.; Pigg, K.B. (22 March 2010). "Floristic composition and comparison of middle Eocene to late Eocene and Oligocene floras in North America". Bulletin of Geosciences: 111–134. doi:10.3140/bull.geosci.1135. 
  127. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  128. Floyd, Andrea E. (2007). "Evolution of the equine digit and its relevance to the modern horse". Equine podiatry. Philadelphia, Pa.: Elsevier Saunders. ISBN 9781416064596. 
  129. Prothero, Donald R. (2002). "Cloven hooves". Horns, tusks, and flippers : the evolution of hoofed mammals. Baltimore: Johns Hopkins University Press. p. 19. ISBN 9780801871351. Retrieved 10 August 2021. 
  130. Prothero, Donald R. (1985). "North American mammalian diversity and Eocene–Oligocene extinctions". Paleobiology 11 (4): 389–405. doi:10.1017/S0094837300011696. 
  131. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  132. Barberà, X.; Cabrera, L.; Marzo, M.; Parés, J.M.; Agustı́, J. (April 2001). "A complete terrestrial Oligocene magnetobiostratigraphy from the Ebro Basin, Spain". Earth and Planetary Science Letters 187 (1-2): 1–16. doi:10.1016/S0012-821X(01)00270-9. 
  133. Prothero, D. (2013). Rhinoceros Giants: The Palaeobiology of Indricotheres. Indiana: Indiana University Press. ISBN 978-0-253-00819-0. 
  134. Torsvik & Cocks 2017, p. 255.
  135. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  136. Mott, Maryann (2006-01-11). "Cats Climb New family Tree". National Geographic News. Retrieved 2006-07-15.
  137. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  138. Zanazzi, Alessandro; Kohn, Matthew J.; MacFadden, Bruce J.; Terry, Dennis O. (February 2007). "Large temperature drop across the Eocene–Oligocene transition in central North America". Nature 445 (7128): 639–642. doi:10.1038/nature05551. 
  139. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  140. Benton, Rachel C.; Terry, Dennis O., Jr.; Evanoff, Emmett; McDonald, Hugh Gregory (2015). The White River Badlands : geology and paleontology. Bloomington. ISBN 9780253016089. Retrieved 10 August 2021. 
  141. Saarinen, Juha; Mantzouka, Dimitra; Sakala, Jakub (2020). "Aridity, Cooling, Open Vegetation, and the Evolution of Plants and Animals During the Cenozoic". Nature through Time: 83–107. doi:10.1007/978-3-030-35058-1_3. 
  142. Flynn, John J; Wyss, André R; Croft, Darin A; Charrier, Reynaldo (June 2003). "The Tinguiririca Fauna, Chile: biochronology, paleoecology, biogeography, and a new earliest Oligocene South American Land Mammal ‘Age’". Palaeogeography, Palaeoclimatology, Palaeoecology 195 (3-4): 229–259. doi:10.1016/S0031-0182(03)00360-2. 
  143. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  144. Benton, M. J. (2019). Cowen's history of life (Sixth ed.). Hoboken, NJ: John Wiley & Sons Ltd. ISBN 9781119482215. 
  145. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  146. Vinn, O. (2009). "The ultrastructure of calcareous cirratulid (Polychaeta, Annelida) tubes". Estonian Journal of Earth Sciences 58 (2): 153–156. doi:10.3176/earth.2009.2.06. Retrieved 2012-09-16. 
  147. Handwerk, Brian (2009-03-22). "Seal with "Arms" Discovered". National Geographic News. Retrieved 2014-12-31.
  148. Green, William; Hunt, G.; Wing, S.; DiMichele, W. (2011). "Does extinction wield an axe or pruning shears? How interactions between phylogeny and ecology affect patterns of extinction". Paleobiology 37 (1): 72–91. doi:10.1666/09078.1. 
  149. Bosellini, Francesca; Perrin, Christine (February 2008). "Estimating Mediterranean Oligocene–Miocene sea surface temperatures: An approach based on coral taxonomic richness". Palaeogeography, Palaeoclimatology, Palaeoecology. 1-2 258 (1–2): 71–88. doi:10.1016/j.palaeo.2007.10.028. 
  150. Mackensen, Andreas (Dec 2004). "Changing Southern Ocean palaeocirculation and effects on global climate". Antarctic Science 16 (4): 369–389. doi:10.1017/S0954102004002202. 
  151. Hay, William; Flogel, S.; Soding, E. (September 2004). "Is initiation of glaciation on Antarctica related to a change in the structure of the ocean?". Global and Planetary Change. 1-3 45 (1–3): 23–33. doi:10.1016/j.gloplacha.2004.09.005. 
  152. Prothero, D. (May 2005). Tertiary to Present | Oligocene. Encyclopedia of Geology. pp. 472–478. doi:10.1016/B0-12-369396-9/00056-3. ISBN 978-0-12-369396-9.
  153. "ICS - Chart/Time Scale".
  154. 154.0 154.1 Alroy, John. "Mammal Paleogene zones". p. The Paleobiology Database. Retrieved 15 July 2009.
  155. 155.0 155.1 155.2 155.3 155.4 "Ancient Climate Change Meant Antarctica Was Once Covered with Palm Trees". Smithsonian Magazine.
  156. 156.0 156.1 "The Eocene Epoch". University of California - Museum of Paleontology.
  157. 157.0 157.1 "Simulation of the Middle Miocene Climate Optimum". University of Michigan.
  158. Dr. David E. Pitts. "Disasters Class Notes - Chapter 12: Climate Change". University of Houston-Clear Lake. Retrieved 31 December 2020.
  159. "ICS - Chart/Time Scale".
  160. "International Commission of Stratigraphy" (PDF). International Commission of Stratigraphy. Retrieved 15 August 2017.
  161. "ICS - Chart/Time Scale".
  162. "ICS - Chart/Time Scale".
  163. "ICS - Chart/Time Scale".
  164. "ICS - Chart/Time Scale".
  165. "ICS - Chart/Time Scale".
  166. "ICS - Chart/Time Scale".
  167. Mariusz A. Salamon; Przemysław Gorzelak; Bruno Ferré; Rafał Lach (October 2010). "Roveacrinids (Crinoidea, Echinodermata) survived the Cretaceous-Paleogene (K-Pg) extinction event". Geology 38 (10): 883-5. doi:10.1130/G31175.1. Retrieved 2016-10-25. 
  168. Dmitry A. Ruban (2009). "The survival of megafauna after the end-Pleistocene impact: a lesson from the Cretaceous/Tertiary boundary". Geologos 15 (2): 129–32. Retrieved 2016-10-25. 
  169. 169.0 169.1 Marcin Machalski (2005). "Late Maastrichtian and earliest Danian scaphitid ammonites from central Europe: Taxonomy, evolution, and extinction". Acta Palaeontologica Polonica 50 (4): 653–96. Retrieved 2016-10-25. 
  170. J.E. Fassett; S.G. Lucas; R.A. Zielinski; J.R. Budahn (May 2001). SG Lucas. ed. Compelling new evidence for Paleocene dinosaurs in the Ojo Alamo Sandstone, San Juan Basin, New Mexico and Colorado, USA, In: Catastrophic events and mass extinctions, Lunar and Planetary Contribution. 1053. pp. 45-6. Bibcode: 2001caev.conf.3139F. Retrieved 2014-08-29. 
  171. James E. Fassett; Larry M. Heaman; Antonio Simonetti (January 2011). "Direct U-Pb dating of Cretaceous and Paleocene dinosaur bones, San Juan Basin, New Mexico". Geology 39 (2): 159-62. doi:10.1130/G31466.1. Retrieved 2016-10-25. 
  172. Larry M. Heaman; Antonio Simonetti; James E. Fassett (11 May 2012). "IN SITU GEOCHEMICAL, SR ISOTOPIC AND U-PB DATING OF DINOSAUR BONE: A RECORD OF FOSSILIZATION AND FLUID-FLOW HISTORY IN THE SAN JUAN BASIN, NEW MEXICO". Abstracts with Programs 44 (6): 86. Retrieved 2016-10-25. 
  173. 173.0 173.1 Sietske Batenburg, Vicente Gilabert, Ignacio Arenillas and José Antonio Arz (20 September 2021). "Extreme Volcanism Did Not Cause The Massive Extinction Of Species In The Late Cretaceous". Science Blog. Retrieved 20 September 2021.{{cite web}}: CS1 maint: multiple names: authors list (link)
  174. Vicente Gilabert (20 September 2021). "Extreme Volcanism Did Not Cause The Massive Extinction Of Species In The Late Cretaceous". Science Blog. Retrieved 20 September 2021.
  175. Cretaceous Atlas of Ancient Life (12 August 2021). "Baculites Species present in the Cretaceous of the Western Interior Seaway". Bethsda, Maryland USA: Digital Atlas of Ancient Life, National Science Foundation. Retrieved 12 August 2021.
  176. Steve Diem and J. David Archibald (2005). "RANGE EXTENSION OF SOUTHERN CHASMOSAURINE CERATOPSIAN DINOSAURS INTO NORTHWESTERN COLORADO". Journal of Paleontology 79 (2): 251-258. doi: Retrieved 11 August 2021. 
  177. 177.0 177.1 James E. Fassett and Maureen B. Steiner (1997). Anderson, O.; Kues, B.; Lucas, S. ed. Precise age of C33N-C32R magnetic-polarity reversal, San Juan Basin, New Mexico and Colorado, In: Mesozoic Geology and Paleontology of the Four Corners Area. New Mexico Geological Society. pp. 239-247. Retrieved 11 August 2021. 
  178. Michael H. Hofmann, Anton Wroblewski and Ron Boyd (25 May 2011). "Mechanisms controlling the clustering of fluvial channels and the compensational stacking of cluster belts". Journal of Sedimentary Research 81: 670–685. doi:10.2110/jsr.2011.54. Retrieved 12 August 2021. 
  179. Mychaluk, K.A.; Levinson, A.A.; Hall, R.H.. "Ammolite: Iridescent fossil ammonite from southern Alberta, Canada.". Gems & Gemology 37 (1): 4-25. Retrieved 2015-01-11. 
  180. Cretaceous Atlas of Ancient Life (2006). "Acanthoceras amphibolum". Bethesda, Maryland USA: Digital Atlas of Ancient Life, National Science Foundation. Retrieved 13 August 2021.
  181. Ammonites
  182. Claire E. L. Still The effects of sexual dimorphism on survivorship in fossil ammonoids: A role for sexual selection in extinction
  183. GBIF
  184. 184.0 184.1 A. S. Gale. "Field Meeting at Folkestone Warren, 29th November, 1987". Proceedings of the Geological Association 100 (1): 73-82. Retrieved 14 August 2021. 
  185. International Commission on Stratigraphy. International Stratigraphic Chart. Retrieved 2008-06-17. 
  186. Kennedy, W.J.; Gale, A.S.; Lees, J.A. & Caron, M. (2004). "The Global Boundary Stratotype Section and Point (GSSP) for the base of the Cenomanian Stage, Mont Risou, Hautes-Alpes, France". Episodes 27: 21–32. 
  187. 187.0 187.1 187.2 JM Watson (28 July 1997). Index Fossils. Reston, Virginia USA: US Geological Survey. Retrieved 2015-01-28. 
  188. 188.0 188.1 Benton, Michael J. (2012). Prehistoric Life. Edinburgh, Scotland: Dorling Kindersley. pp. 44–45. ISBN 978-0-7566-9910-9. 
  189. For a detailed geologic timescale see Gradstein et al. (2004)
  190. See Gradstein et al. (2004) for a detailed geologic timescale
  191. Meister et al. (2006)
  192. Christian Meister, Martin Aberhan, Joachim Blau, Jean-Louis Dommergues, Susanne Feist-Burkhardt, Ernie A. Hailwood, Malcom Hart, Stephen P. Hesselbo, Mark W. Hounslow, Mark Hylton, Nicol Morton1, Kevin Page, and Greg D. Price (1 June 2006). "The Global Boundary Stratotype Section and Point (GSSP) for the base of the Pliensbachian Stage (Lower Jurassic), Wine Haven, Yorkshire, UK". Episodes 29 (2): 93-106. doi:10.18814/epiiugs/2006/v29i2/003. Retrieved 10 August 2021. 
  193. Spencer G. Lucas; Jean Guex; Lawrence H. Tanner; David Taylor; Wolfram M. Kuerschner Viorel Atudorei; Annachiara Bartolini (April 2005). "Definition of the Triassic-Jurassic boundary". Albertiana 32 (4): 12-35. Retrieved 2015-01-21. 
  194. 194.0 194.1 A V Hillebrandt; L Krystyn; W M Kürschner; N R Bonis; M Ruhl; S Richoz; M A N Schobben; M Urlichs et al. (September 2013). "The Global Stratotype Sections and Point (GSSP) for the base of the Jurassic System at Kuhjoch (Karwendel Mountains, Northern Calcareous Alps, Tyrol, Austria)". Episodes 36 (3): 162-98. Retrieved 2015-01-21. 
  195. 195.0 195.1 Yin Hongfu, Zhang Kexin, Tong Jinnan, Yang Zunyi and Wu Shunbao (June). [ "The Global Stratotype Section and Point (GSSP) of the Permian-Triassic Boundary"]. Episodes 24 (2): 102-14. Retrieved 2015-01-20. 
  196. IONHexamoceras (15 April 2015). "Name - Hexamoceras". Thomson Reuters. Retrieved 2015-04-15.
  197. C. H. Holland (October 1987). "Aptychopsid Plates (Nautiloid Opercula) from the Irish Silurian". The Irish Naturalists' Journal 22 (8): 347-51. Retrieved 2015-04-15. 
  198. "International Chronostratigraphic Chart v.2015/01" (PDF). International Commission on Stratigraphy. January 2015.
  199. J.C. Gutiérrez-Marco; D. Goldman; J. Reyes-Abril; J. Gómez (2011). J.C. Gutiérrez-Marco. ed. A Preliminary Study of Some Sandbian (Upper Ordovician) Graptolites from Venezuela, In: Ordovician of the World. Madrid: Instituto Geológico y Minero de España. pp. 199-206. ISBN 978-84-7840-857-3. Retrieved 2015-01-15. 
  200. 200.00 200.01 200.02 200.03 200.04 200.05 200.06 200.07 200.08 200.09 200.10 200.11 200.12 200.13 200.14 Lauren Pouille, Olga Obut, Taniel Danelian and Nikolay Sennikov (November 2011). "Lower Cambrian (Botomian) polycystine Radiolaria from the Altai Mountains (southern Siberia, Russia)". Comptes Rendus Palevol 10 (8): 627-633. doi:10.1016/j.crpv.2011.05.004. Retrieved 18 March 2022. 
  201. 201.0 201.1 201.2 201.3 Stitt, J. H.; Rucker, J. D.; Diane Boyer, N.; Hart, W. D. (1994). "New Elvinia Zone (Upper Cambrian) Trilobites from New Localities in the Collier Shale, Ouachita Mountains, Arkansas". Journal of Paleontology 68 (3): 518–523. doi:10.1017/s0022336000025890. 
  202. Robison, R. A. (1964). "Upper Middle Cambrian Stratigraphy of Western Utah". Geological Society of America Bulletin 75 (10): 995–1010. doi:10.1130/0016-7606(1964)75[995:UMCSOW]2.0.CO;2. ISSN 0016-7606. 
  203. 203.0 203.1 Zhengfu Zhao, Nicolas Thibault, Tais W. Dahl, Niels H. Schovsbo, Aske L. Sørensen, Christian M.Ø. Rasmussen, and Arne T. Nielsen (April 2021). Synchronizing Rock Clocks in the Cambrian, In: vEGU21, the 23rd EGU General Assembly. EGU21. Online: European Geosciences Union (EGU). pp. 5082. doi:10.5194/egusphere-egu21-5082. Bibcode: 2021EGUGA..23.5082Z. Retrieved 24 March 2022. 
  204. Palmer, A.R. (1998). "A proposed nomenclature for stages and series for the Cambrian of Laurentia". Canadian Journal of Earth Sciences 35 (4): 323–328. doi:10.1139/cjes-35-4-323. ISSN 1480-3313. 
  205. 205.0 205.1 Landing, E.; Westrop, S.R.; Adrain, J.M. (19 September 2011). "The Lawsonian Stage - the Eoconodontus notchpeakensis FAD and HERB carbon isotope excursion define a globally correlatable terminal Cambrian stage". Bulletin of Geosciences: 621–640. doi:10.3140/bull.geosci.1251. 
  206. 206.0 206.1 This is just younger than the Bathyuriscus-Elrathina zone, or at least just younger than the Stephen Formation. See
  207. Griswold, L.S. (1892). "Whetstones and the novaculites". Annual Report of the Geological Survey of Arkansas for 1890 3. 
  208. Purdue, Albert Homer (1909). Slates of Arkansas. Geological Survey of Arkansas. pp. 30, 31. 
  209. Purdue, Albert Homer (1909). "Structure and stratigraphy of the Ouachita Ordovician area, Arkansas (abstract)". Geological Society of America Bulletin 19: 557. doi:10.1130/GSAB-19-513. 
  210. 210.0 210.1 210.2 210.3 210.4 210.5 210.6 210.7 210.8 Hohensee, Steven; Stitt, James (November 1989). "Redeposited Elvinia Zone (Upper Cambrian) trilobites from the Collier Shale, Ouachita Mountains, west-central Arkansas". Journal of Paleontology 63 (6): 857–879. doi:10.1017/s0022336000036544. 
  211. 211.00 211.01 211.02 211.03 211.04 211.05 211.06 211.07 211.08 211.09 211.10 211.11 211.12 211.13 Hart, William; Stitt, James; Hohensee, Steven; Ethington, Raymond (May 1987). "Geological implications of Late Cambrian trilobites from the Collier Shale, Jessieville area, Arkansas". Geology 15 (5): 447–450. doi:10.1130/0091-7613(1987)15<447:giolct>;2. 
  212. "Stratigraphic Chart". International Commission on Stratigraphy. Retrieved 17 November 2012.{{cite web}}: CS1 maint: url-status (link)
  213. "GSSP Table - Paleozoic Era". Geologic Timescale Foundation. Retrieved 17 November 2012.
  214. 214.00 214.01 214.02 214.03 214.04 214.05 214.06 214.07 214.08 214.09 214.10 214.11 214.12 214.13 I. V. Korovnikov (may 2014). [ "Trilobites Plicatolina lucida Lazarenko from the Upper Cambrian of the Kharaulakh Mountains (Northeastern Siberian Platform)"]. Paleontological Journal 48 (5): 465-470. doi:10.1134/S0031030114050050. Retrieved 24 March 2022. 
  215. Tasch, P. (1951). "Fauna and paleoecology of the Upper Cambrian Warrior Formation of central Pennsylvania". Journal of Paleontology 25 (3): 275–306.  cited in Uta Merkel. "Highway No. 322 near Waddle, Bed 11.12". Fossilworks. Retrieved 17 December 2021.
  216. "International Chronostratigraphic Chart". ICS. Retrieved 12 November 2012.
  217. 217.0 217.1 217.2 Peng, Shanchi; Babcock, Loren; Zuo, Jingxun; Lin, Huanling; Yang, Xianfeng; Qi, Yuping; Bagnoli, Gabriella; Wang, Longwu (December 2012). "Global Standard Stratotype-Section and Point (GSSP) for the Base of the Jiangshanian Stage (Cambrian: Furongian) at Duibian, Jiangshan, Zhejiang, Southeast China". Episodes 35 (4): 462-477. doi:10.18814/epiiugs/2012/v35i4/002. Retrieved 13 December 2020. 
  218. Saltzman, M. R.; Cowan, C. A.; Runkel, A. C.; Runnegar, B.; Stewart, M. C.; Palmer, A. R. (2004-05-01). "The Late Cambrian Spice (13C) Event and the Sauk II-SAUK III Regression: New Evidence from Laurentian Basins in Utah, Iowa, and Newfoundland". Journal of Sedimentary Research 74 (3): 366–377. doi:10.1306/120203740366. ISSN 1527-1404. 
  219. Gerhardt, Angela M.; Gill, Benjamin C. (2016-11-01). "Elucidating the relationship between the later Cambrian end-Marjuman extinctions and SPICE Event". Palaeogeography, Palaeoclimatology, Palaeoecology 461: 362–373. doi:10.1016/j.palaeo.2016.08.031. ISSN 0031-0182. 
  220. Saltzman, Matthew R.; Ripperdan, Robert L.; Brasier, M. D.; Lohmann, Kyger C.; Robison, Richard A.; Chang, W. T.; Peng, Shanchi; Ergaliev, E. K. et al. (2000-10-01). "A global carbon isotope excursion (SPICE) during the Late Cambrian: relation to trilobite extinctions, organic-matter burial and sea level". Palaeogeography, Palaeoclimatology, Palaeoecology 162 (3): 211–223. doi:10.1016/S0031-0182(00)00128-0. ISSN 0031-0182. 
  221. Wotte, Thomas; Strauss, Harald (2015). "Questioning a widespread euxinia for the Furongian (Late Cambrian) SPICE event: indications from δ13C, δ18O, δ34S and biostratigraphic constraints". Geological Magazine 152 (6): 1085–1103. doi:10.1017/S0016756815000187. ISSN 0016-7568. 
  222. LeRoy, Matthew A.; Gill, Benjamin C.; Sperling, Erik A.; McKenzie, N. Ryan; Park, Tae-Yoon S. (2021-03-15). "Variable redox conditions as an evolutionary driver? A multi-basin comparison of redox in the middle and later Cambrian oceans (Drumian-Paibian)". Palaeogeography, Palaeoclimatology, Palaeoecology 566: 110209. doi:10.1016/j.palaeo.2020.110209. ISSN 0031-0182. 
  223. Schmid, Susannea, Smith, Patrick Mark, and Woltering, Martijn (1 November 2018). "A basin-wide record of the Late Cambrian Steptoean positive carbon isotope excursion (SPICE) in the Amadeus Basin, Australia". Palaeogeography, Palaeoclimatology, Palaeoecology 508: 116-128. doi:10.1016/j.palaeo.2018.07.027. Retrieved 27 March 2022. 
  224. "GeoWhen Database - Maentwrogian".
  225. Peters, S.E. (2003). Paleontology and taphonomy of the Upper Weeks Formation (Cambrian, Upper Marjuman, Cedaria Zone) of western Utah. University of Chicago. 
  226. Pratt, B.R. (1992). "Trilobites of the Marjuman and Steptoean stages (Upper Cambrian), Rabbitkettle Formation, southern Mackenzie Mountains, northwest Canada". Palaeontographica Canadiana (9): 1–109.  cited in Shanan Peters. "Section N - collection N-33". Fossilworks. Retrieved 17 December 2021.
  227. Sepkoski Jr., J.J. (1998). "Rates of speciation in the fossil record". Philosophical Transactions of the Royal Society of London B: Biological Sciences 353 (1366): 315–326. doi:10.1098/rstb.1998.0212. PMID 11541734. PMC 1692211. //  cited in Mike Sommers. "Central Texas, Riley Fm., Texas". Fossilworks. Retrieved 17 December 2021.
  228. Pojeta, J.; Gilbert-Tomlinson, J.; Shergold, J.H. (1977). "Cambrian and Ordovician rostroconch molluscs from Northern Australia". Australian Bureau of Mineral Resources, Geology and Geophysics Bulletin 171: 1–54.  cited in Pete Wagner. "Locality 50. G127*. Glenormiston". Fossilworks. Retrieved 17 December 2021.
  229. Bordonaro, O.L.; Fojo, C.F. (2011). "Bathyuriscus mendozanus (Rusconi, 1945), trilobites del Cámbrico medio de la Precordillera Argentina [Bathyuriscus mendozanus (Rusconi, 1945), middle Cambrian trilobites from the Argentine Precordillera"]. Revista Española de Paleontología 26 (1): 11–23. ISSN 0213-6937. Retrieved 30 June 2013. 
  230. Coppold, Murray and Wayne Powell (2006). A Geoscience Guide to the Burgess Shale, p.56. The Burgess Shale Geoscience Foundation, Field, British Columbia. ISBN 0-9780132-0-4.
  231. Rhodes, Frank H. T.; Herbert S. Zim; Paul R. Shaffer (1962). Fossils: A Guide to Prehistoric Life. New York City, NY, USA: Western Publishing Company, Inc.. pp. 95. 
  232. 232.0 232.1 "GSSP for Guzhangian Stage". Retrieved 12 November 2012.
  233. 233.0 233.1 233.2 Shanchi Peng; Loren E. Babcock; Jingxun Zuo; Huanling Lin; Xuejian Zhu; Xianfeng Yang; Richard A. Robison; Yuping Qi et al. (March 2009). "The Global Boundary Stratotype Section and Point (GSSP) of the Guzhangian Stage (Cambrian) in the Wuling Mountains, Northwestern Hunan, China". Episodes 32 (1): 41-55. Retrieved 2015-01-21. 
  234. 234.0 234.1 Peng, S.; Robison, R.A. (2000). "Agnostid biostratigraphy across the Middle-Upper Cambrian boundary in Hunan, China". Journal of Paleontology Memoir 53.  cited in Austin Hendy. "Paibi section, bed 37a". Fossilworks. Retrieved 17 December 2021.
  235. 235.0 235.1 Peng, S. C.; Babcock, L. E.; Robison, R. A.; Lin, H. L.; Rees, M. N.; Saltzman, M. R. (2004). "Global Standard Stratotype-Section and Point (GSSP) of the Furongian Series and Paibian Stage (Cambrian)". Lethaia 37 (4): 365–379. doi:10.1080/00241160410002081. Retrieved 8 December 2020. 
  236. Gozalo, Rodolfo; Álvarez, María Eugenia Dies; Vintaned, José Antonio Gámez; Zhuravlev, Andrey Yu.; Bauluz, Blanca; Subías, Ignacio; Chirivella Martorell, Juan B.; Mayoral, Eduardo et al. (1 December 2011). "Proposal of a reference section and point for the Cambrian Series 2-3 boundary in the Mediterranean subprovince in Murero (NE Spain) and its intercontinental correlation". Geological Journal 48 (2–3): 142–155. doi:10.1002/gj.1330. 
  237. 237.0 237.1 "GSSP Table - Paleozoic Era". Retrieved 15 November 2012.
  238. 238.0 238.1 Yuanlong Zhao; Jinliang Yuan; Loren E. Babcock; Qingjun Guo; Jin Peng; Leiming Yin; Xinglian Yang; Shanchi Peng et al. (June 2019). "Global Standard Stratotype-Section and Point (GSSP) for the conterminous base of the Miaolingian Series and Wuliuan Stage (Cambrian) at Balang, Jianhe, Guizhou, China". Episodes 42 (2): 165–184. doi:10.18814/epiiugs/2019/019013. Retrieved 8 December 2020. 
  239. 239.0 239.1 Kimmig, J., Strotz, L.C., Kimmig, S.R., Egenhoff, S.O., Lieberman, B.S. 2019. The Spence Shale Lagerstätte: an important window into Cambrian biodiversity. Journal of the Geological Society of London, 176, 609–619
  240. Walcott, C.D. 1908. Cambrian Geology and Palaeontology. Smithsonian Museum, Miscellaneous Collections, 53.
  241. Stoyanow, A. (1958). "Sonoraspis and Albertella in the Inyo Mountains, California". Geological Society of America Bulletin 69 (3): 347–352. doi:10.1130/0016-7606(1958)69[347:SAAITI]2.0.CO;2. ISSN 0016-7606. 
  242. Conway Morris, S.; Robison, R.A. (1986). "Middle Cambrian priapulids and other soft-bodied fossils from Utah and Spain". University of Kansas Paleontological Contributions 117: 1–22.  cited on Paul Hearn. "Lower Wheeler Shale". Fossilworks. Retrieved 17 December 2021.
  243. Robison, R.A. (1971). "Additional Middle Cambrian trilobites from the Wheeler Shale of Utah". Journal of Paleontology 45 (5): 796–804.  cited on Shenan Peeters. "Wheeler Formation, House Range, Utah". Fossilworks. Retrieved 17 December 2021.
  244. SemperBlotto (4 March 2007). "Burgess Shale". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 29 March 2022. {{cite web}}: |author= has generic name (help)
  245. Butterfield, N. J. (2003-02-01). "Exceptional Fossil Preservation and the Cambrian Explosion". Integrative and Comparative Biology 43 (1): 166–177. doi:10.1093/icb/43.1.166. ISSN 1540-7063. 
  246. Gabbott, Sarah E. (2001). Exceptional Preservation. doi:10.1038/npg.els.0001622. ISBN 978-0-470-01590-2. 
  247. Butterfield, N.J. (2006). "Hooking some stem-group" worms": fossil lophotrochozoans in the Burgess Shale". BioEssays 28 (12): 1161–6. doi:10.1002/bies.20507. PMID 17120226. 
  248. 248.0 248.1 248.2 Loren E. Babcock; Richard A. Robison; Margaret N. Rees; Shanchi Peng; Matthew R. Saltzman (June 2007). "The Global boundary Stratotype Section and Point (GSSP) of the Drumian Stage (Cambrian) in the Drum Mountains, Utah, USA". Episodes 30 (2): 84-94. Retrieved 2016-10-26. 
  249. Samuel M. Gon III. "Agnostida Fact Sheet". A Guide to the Orders of Trilobites. Retrieved 18 November 2012.
  250. Brian D. E. Chatterton, Desmond H. Collins & Rolf Ludvigsen (2003). "Cryptic behaviour in trilobites: Cambrian and Silurian examples from Canada, and other related occurrences". In Philip D. Lane, Derek J. Siveter & Richard A. Fortey. Trilobites and their Relatives: contributions from the third international conference, Oxford 2001. Special Papers in Palaeontology. 70. pp. 157–173. 
  251. Coppold, Murray and Wayne Powell (2006). A Geoscience Guide to the Burgess Shale, p.56. The Burgess Shale Geoscience Foundation, Field, British Columbia. ISBN 0-9780132-0-4
  253. 253.0 253.1 253.2 Jean-Bernard Caron; Martin R. Smith; Thomas H. P. Harvey (31 July 2013). "Beyond the Burgess Shale: Cambrian microfossils track the rise and fall of hallucigeniid lobopodians". Proceedings of the Royal Society B 280 (1767): 1613. doi:10.1098/rspb.2013.1613. Retrieved 2016-10-26. 
  254. 254.0 254.1 Moore, R. A.; Lieberman, B. S. (2009). "Preservation of Early and Middle Cambrian soft-bodied arthropods from the Pioche Shale, Nevada, USA". Palaeogeography, Palaeoclimatology, Palaeoecology 277: 57–62. doi:10.1016/j.palaeo.2009.02.014. 
  255. 255.0 255.1 Lieberman, B. S. (2003). "A New Soft-Bodied Fauna: the Pioche Formation of Nevada". Journal of Paleontology 77 (4): 674–690. doi:10.1666/0022-3360(2003)077<0674:ANSFTP>2.0.CO;2. ISSN 0022-3360. 
  256. 256.0 256.1 256.2 256.3 Peng, S.C.; Babcock, L.E. (21 September 2011). "Continuing progress on chronostratigraphic subdivision of the Cambrian System". Bulletin of Geosciences: 391–396. doi:10.3140/bull.geosci.1273. Retrieved 21 November 2012. 
  257. Sundberg, F. A. (2005). "The Topazan Stage, a New Laurentian Stage (Lincolnian Series_ "Middle" Cambrian)". Journal of Paleontology (Paleontological Society) 79 (1): 63–71. doi:10.1666/0022-3360(2005)079<0063:TTSANL>2.0.CO;2. 
  258. 258.0 258.1 Webster, Mark (2011). "Trilobite Biostratigraphy and Sequence Stratigraphy of the Upper Dyeran (traditional Laurentian "Lower Cambrian) in the southern Great Basis, USA". Museum of Northern Arizona Bulletin 67. 
  259. 259.0 259.1 Zhuravlev, Andrey Yu.; Wood, Rachel A. (1996). "Anoxia as the cause of the mid-Early Cambrian (Botomian) extinction event". Geology 24 (4): 311. doi:10.1130/0091-7613(1996)024<0311:aatcot>;2. ISSN 0091-7613. 
  260. Signor, Philip W. (1992). "Taxonomic diversity and faunal turnover in the Early Cambrian: Did the most severe mass extinction of the Phanerozoic occur in the Botomian stage?". The Paleontological Society Special Publications 6: 272. doi:10.1017/S2475262200008327. ISSN 2475-2622. 
  261. Zhuravlev, Andrey Yu. (1996). "Reef ecosytem recovery after the Early Cambrian extinction". Geological Society, London, Special Publications 102 (1): 79–96. doi:10.1144/GSL.SP.1996.001.01.06. ISSN 0305-8719. 
  262. Porter, S.M. (May 2004). "Halkieriids in Middle Cambrian Phosphatic Limestones from Australia". Journal of Paleontology 78 (3): 574–590. doi:10.1666/0022-3360(2004)078<0574:HIMCPL>2.0.CO;2.;col1. Retrieved 2008-08-01. 
  263. Debrenne, Françoise (1991). "Extinction of the Archaeocyatha". Historical Biology 5 (2–4): 95–106. doi:10.1080/10292389109380393. ISSN 0891-2963. 
  264. 264.0 264.1 264.2 264.3 J.B. Jago, Wen-Long Zang, Xiaowen Sun, G.A. Brock, J.R. Paterson, C.B. Skovsted (16 October 2006). "A review of the Cambrian biostratigraphy of South Australia". Palaeoworld 15: 406-423. doi:10.1016/j.palwor.2006.10.014. Retrieved 20 March 2022. 
  265. Paleobiology Database
  266. F. R. Abe, B. S. Lieberman, M. C. Pope, K. Dilliard (2010). "New information on olenelline trilobites from the Cambrian Sekwi Formation in northwestern Canada". Canadian Journal of Earth Sciences, 2010, 47 (12): 1445–1449.[1]
  267. Life Desks, Trilobites on line
  268. Life Desks, Trilobites on line
  269. U. S. National Museum, Catalogue No. 60082.
  270. 270.0 270.1 K.H. Mahan, B.P. Wernicke, and M.J. Jercinovic (15 January). "Th–U–total Pb geochronology of authigenic monazite in the Adelaide rift complex, South Australia, and implications for the age of the type Sturtian and Marinoan glacial deposits". Earth and Planetary Science Letters 289 (1-2): 76-86. Retrieved 2015-01-17. 
  271. Ilya Bobrovskiy (20 September 2018). Earliest animal fossils are identified. BBC. Retrieved 23 September 2018. 
  272. 272.0 272.1 Jochen Brocks (20 September 2018). Earliest animal fossils are identified. BBC. Retrieved 23 September 2018. 
  273. SemperBlotto (1 June 2005). "Ediacaran". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 10 March 2019. {{cite web}}: |author= has generic name (help)
  274. 274.0 274.1 274.2 Pu, Judy P.; Bowring, Samuel A.; Ramezani, Jahandar; Myrow, Paul; Raub, Timothy D.; Landing, Ed; Mills, Andrea; Hodgin, Eben et al. (2016). "Dodging snowballs: Geochronology of the Gaskiers glaciation and the first appearance of the Ediacaran biota". Geology 44 (11): 955. doi:10.1130/G38284.1. 
  275. Rooney, Alan D.; Strauss, Justin V.; Brandon, Alan D.; Macdonald, Francis A. (2015). "A Cryogenian chronology: Two long-lasting synchronous Neoproterozoic glaciations". Geology 43 (5): 459–462. doi:10.1130/G36511.1. 
  276. Shields, G. A. (2008). "Palaeoclimate: Marinoan meltdown". Nature Geoscience 1 (6): 351–353. doi:10.1038/ngeo214. 
  277. Kennedy, M.; Mrofka, D.; von Der Borch, C. (2008). "Snowball Earth termination by destabilization of equatorial permafrost methane clathrate". Nature 453 (7195): 642–5. doi:10.1038/nature06961. PMID 18509441. 
  278. George E. Williams; Victor A. Gostin; David M. McKirdy; Wolfgang V. Preiss; Phillip W. Schmidt (2011). "The Elatina glaciation (late Cryogenian), South Australia". Geological Society, London, Memoirs 36: 713-721. doi:10.1144/M36.70. Retrieved 13 March 2019. 
  279. SemperBlotto (1 June 2005). "Cryogenian". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 9 March 2019. {{cite web}}: |author= has generic name (help)
  280. Dave Lawrence (2003). "Microfossil lineages support sloshy snowball Earth". Geotimes.
  281. 281.0 281.1 T. Bosak, D.J.G. Lahr, S.B. Pruss, F.A. Macdonald, L. Dalton, E. Matys (1 August 2011). "Agglutinated tests in post-Sturtian cap carbonates of Namibia and Mongolia". Earth and Planetary Science Letters 308 (1-2): 29-40. doi:10.1016/j.epsl.2011.05.030. Retrieved 30 July 2021. 
  282. Porter, S.A. & Knoll, A.H. (2000). "Testate amoeba in the Neoproterozoic Era: evidence from vase-shaped microfossils in the Chuar Group, Grand Canyon". Paleobiology 26 (3): 360–385.. doi:10.1666/0094-8373(2000)026<0360:TAITNE>2.0.CO;2. ISSN 0094-8373. 
  283. Brain, C. K.; Prave, A. R.; Hoffmann, K. H.; Fallik, A. E.; Herd D. A.; Sturrock, C.; Young, I.; Condon, D. J. et al. (2012). "The first animals: ca. 760-million-year-old sponge-like fossils from Namibia". South African Journal of Science 108 (8): 1–8. doi:10.4102/sajs.v108i1/2.658. 
  284. Gordon D. Love1; Emmanuelle Grosjean; Charlotte Stalvies; David A. Fike; John P. Grotzinger; Alexander S. Bradley; Amy E. Kelly; Maya Bhatia et al. (2009). "Fossil steroids record the appearance of Demospongiae during the Cryogenian period". Nature 457 (7230): 718–721. doi:10.1038/nature07673. PMID 19194449. 
  285. Maloof, Adam C.; Rose, Catherine V.; Beach, Robert; Samuels, Bradley M.; Calmet, Claire C.; Erwin, Douglas H.; Poirier, Gerald R.; Yao, Nan et al. (17 August 2010). "Possible animal-body fossils in pre-Marinoan limestones from South Australia". Nature Geoscience 3 (9): 653–659. doi:10.1038/ngeo934. 
  286. "Discovery of possible earliest animal life pushes back fossil record". 17 August 2010.
  288. Fossil fats reveal how complex life kicked off after Snowball Earth phase
  289. Macdonald, Francis A. "Neoproterozoic Glaciation". Harvard University. Retrieved 17 August 2017.
  290. Rooney, Alan D.; Strauss, Justin V.; Brandon, Alan D.; Macdonald, Francis A. (2015). "A Cryogenian chronology: Two long-lasting synchronous Neoproterozoic glaciations". Geology 43 (5): 459–462. doi:10.1130/G36511.1. 
  291. Kendall, Brian; Creaser, Robert A.; Selby, David (September 2006). "Re-Os geochronology of postglacial black shales in Australia: Constraints on the timing of Sturtian glaciation". Geology 34 (9): 729–732. doi:10.1130/g22775.1. Retrieved 17 August 2017. 
  292. Stern, R.J.; Avigad, D.; Miller, N.R.; Beyth, M. (2006). "Geological Society of Africa Presidential Review: Evidence for the Snowball Earth Hypothesis in the Arabian-Nubian Shield and the East African Orogen". Journal of African Earth Sciences 44 (1): 1–20. doi:10.1016/j.jafrearsci.2005.10.003. 
  293. 293.0 293.1 293.2 293.3 293.4 293.5 293.6 Scott MacLennan, Yuem Park, Nicholas Swanson-Hysell, Adam Maloof, Blair Schoene, Mulubrhan Gebreslassie, Eliel Antilla, Tadele Tesema, Mulugeta Alene, and Bereket Haileab (1 June 2018). "The arc of the Snowball: U-Pb dates constrain the Islay anomaly and the initiation of the Sturtian glaciation". Geology 46 (6): 539-542. doi:10.1130/G40171.1. Retrieved 30 July 2021. 
  294. Corsetti, F.A.; Awramik, S.M.; Pierce, D. (2003-04-15). "A complex microbiota from snowball Earth times: Microfossils from the Neoproterozoic Kingston Peak Formation, Death Valley, USA". Proceedings of the National Academy of Sciences 100 (8): 4399–4404. doi:10.1073/pnas.0730560100. PMID 12682298. PMC 153566. Retrieved 2007-06-28. 
  295. Gutschick, R.C.; Perry, T.G. (1959-11-01). "Sappington (Kinderhookian) sponges and their environment [Montana"]. Journal of Paleontology 33 (6): 977–985. Retrieved 2007-06-28. 
  296. Riding, Robert. 1991. Calcareous Algae and Stromatolites, pp. 32. Springer-Verlag Press.
  297. Porter, S.A.; Knoll, A.H. (2000). "Testate amoeba in the Neoproterozoic Era: evidence from vase-shaped microfossils in the Chuar Group, Grand Canyon". Paleobiology 26 (3): 360–385. doi:10.1666/0094-8373(2000)026<0360:TAITNE>2.0.CO;2. ISSN 0094-8373. 
  298. Love; Grosjean, Emmanuelle; Stalvies, Charlotte; Fike, David A.; Grotzinger, John P.; Bradley, Alexander S.; Kelly, Amy E.; Bhatia, Maya et al. (2009). "Fossil steroids record the appearance of Demospongiae during the Cryogenian period". Nature 457 (7230): 718–721. doi:10.1038/nature07673. PMID 19194449. 
  299. Maloof, Adam C.; Rose, Catherine V.; Beach, Robert; Samuels, Bradley M.; Calmet, Claire C.; Erwin, Douglas H.; Poirier, Gerald R.; Yao, Nan et al. (17 August 2010). "Possible animal-body fossils in pre-Marinoan limestones from South Australia". Nature Geoscience 3 (9): 653–659. doi:10.1038/ngeo934. 
  300. "Discovery of possible earliest animal life pushes back fossil record". 2010-08-17.
  302. Fossil fats reveal how complex life kicked off after Snowball Earth phase
  303. Sokolov B. S. (1965) "Abstracts of All-Union Symposium on Paleontology of the Precambrian and Early Cambrian." Nauka, Novosibirsk.
  304. Rozanov, A.Y.; Missarzhevskij, V.V.; Volkova, N.A.; Voronova, L.G.; Krylov, I.N.; Keller, B.M.; Korolyuk, I.K.; Lendzion, K. et al. (1969). "The Tommotian Stage and the problem of the lower boundary of the Cambrian". Trudy Geologičeskogo Instituta AN SSSR 206: 1–380. 
  305. 305.0 305.1 Sokolov, B.S. (1997). "Essays on the Advent of the Vendian System." 153 pp. KMK Scientific Press, Moscow. (in Russian)
  306. 306.0 306.1 M. A. Fedonkin; B. S. Sokolov; M. A. Semikhatov; N. M. Chumakov (2007). "Vendian versus Ediacaran: priorities, contents, prospectives". Archived from the original on October 4, 2011. In: "The Rise and Fall of the Vendian (Ediacaran) Biota" (PDF). Origin of the Modern Biosphere. Transactions of the International Conference on the IGCP Project 493n Moscow: GEOS. August 20–31, 2007. (82mb)
  307. Khomentovsky, V. V. (2008). "The Yudomian of Siberia, Vendian and Ediacaran systems of the International stratigraphic scale". Stratigraphy and Geological Correlation 16 (6): 581–598. doi:10.1134/S0869593808060014. 
  308. "Tonian Period". GeoWhen Database. Retrieved May 12, 2006.
  309. "Tonian Period". GeoWhen Database. Archived from the original on May 12, 2006. Retrieved January 5, 2006.
  310. 310.0 310.1 James G. Ogg (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia 37 (2): 183–199. doi:10.1080/00241160410006492. 
  311. SemperBlotto (1 June 2005). "Tonian". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 10 March 2019. {{cite web}}: |author= has generic name (help)
  312. Kliman, Richard M. (Apr 14, 2016). Encyclopedia of Evolutionary Biology. Academic Press. p. 251. ISBN 9780128004265. 
  313. Nicholas J. Butterfield (2000). "Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes". Paleobiology 26 (3): 386–404. doi:10.1666/0094-8373(2000)026<0386:BPNGNS>2.0.CO;2. 
  314. Gibson, Timothy M; Shih, Patrick M; Cumming, Vivien M; Fischer, Woodward W; Crockford, Peter W; Hodgskiss, Malcolm S.W; Wörndle, Sarah; Creaser, Robert A et al. (2017). "Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis". Geology 46 (2): 135–138. doi:10.1130/G39829.1. 
  315. 315.0 315.1 J. Boyer (2021). "Ectasian Period". Google. Retrieved 28 July 2021.
  316. Evitt, William R. (1963). "A discussion and proposals concerning fossil dinoflagellates, hystrichospheres, and acritarchs, II". Proceedings of the National Academy of Sciences 49 (3): 298–302. doi:10.1073/pnas.49.3.298. PMID 16591055. PMC 299818. 
  317. Martin, Francine (1993). "Acritarchsa Review". Biological Reviews 68 (4): 475–537. doi:10.1111/j.1469-185X.1993.tb01241.x. 
  318. Colbath, G.Kent; Grenfell, Hugh R. (1995). "Review of biological affinities of Paleozoic acid-resistant, organic-walled eukaryotic algal microfossils (Including "acritarchs")". Review of Palaeobotany and Palynology 86 (3–4): 287–314. doi:10.1016/0034-6667(94)00148-D. 
  319. Colbath, G.Kent; Grenfell, Hugh R. (1995). "Review of biological affinities of Paleozoic acid-resistant, organic-walled eukaryotic algal microfossils (including "acritarchs")". Review of Palaeobotany and Palynology 86 (3–4): 287–314. doi:10.1016/0034-6667(94)00148-d. ISSN 0034-6667. 
  320. "Calymmian Period". GeoWhen Database. Retrieved May 12, 2006.
  321. Sujan Sengupta (2015). Life: A Delicate Process, In: Worlds Beyond Our Own. Cham: Springer. pp. 103-116. doi:10.1007/978-3-319-09894-4_7. ISBN 978-3-319-09893-7. Retrieved 28 July 2021. 
  322. "Statherian Period". GeoWhen Database. Retrieved January 5, 2006.
  323. James G. Ogg (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia 37 (2): 183–199. doi:10.1080/00241160410006492. 
  324. Kumar, S. (2009). "Controversy concerning 'Cambrian' fossils from the Vindhyan sediments: a re-assessment". Journal of the Palaentological Society of India 54 (1): 115–117. 
  325. Bengtson, Stefan; Sallstedt, Therese; Belivanova, Veneta; Whitehouse, Martin (2017). "Three-dimensional preservation of cellular and subcellular structures suggests 1.6 billion-year-old crown-group red algae". PLOS Biology 15 (3): e2000735. doi:10.1371/journal.pbio.2000735. PMID 28291791. PMC 5349422. // 
  326. Bengtson, S.; Belivanova, V.; Rasmussen, B.; Whitehouse, M. (2009). "The controversial "Cambrian" fossils of the Vindhyan are real but more than a billion years older". Proceedings of the National Academy of Sciences 106 (19): 7729–7734. doi:10.1073/pnas.0812460106. PMID 19416859. PMC 2683128. // 
  327. Mukherjee, I.; Large, R. R.; Corkrey, R.; Danyushevsky, L. V. (2018). "The Boring Billion, a slingshot for Complex Life on Earth". Scientific Reports 8 (4432): 4432. doi:10.1038/s41598-018-22695-x. PMID 29535324. PMC 5849639. // 
  328. 328.0 328.1 Hedges, S. B.; Blair, J. E.; Venturi, M. L.; Shoe, J. L. (2004). "A molecular timescale of eukaryote evolution and the rise of complex multicellular life". BMC Evolutionary Biology 4 (2): 2. doi:10.1186/1471-2148-4-2. PMID 15005799. PMC 341452. // 
  329. Bengtson, S.; Sallstedt, T.; Belivanova, V.; Whitehouse, M. (2017). "Three-dimensional preservation of cellular and subcellular structures suggests 1.6 billion-year-old crown-group red algae". PLOS Biology 15 (3): e2000735. doi:10.1371/journal.pbio.2000735. PMID 28291791. PMC 5349422. // 
  330. Loron, C. C.; François, C.; Rainbird, R. H.; Turner, E. C.; Borensztajn, S.; Javaux, E. J. (2019). "Early fungi from the Proterozoic era in Arctic Canada". Nature 70 (7760): 232–235. doi:10.1038/s41586-019-1217-0. PMID 31118507. 
  331. Cooper, G. M. (2000). "The Origin and Evolution of Cells". The Cell: A Molecular Approach (2nd ed.). Sinauer Associates. 
  332. Niklas, K. J. (2014). "The evolutionary-developmental origins of multicellularity". American Journal of Botany 101 (1): 6–25. doi:10.3732/ajb.1300314. PMID 24363320. 
  333. Brooke, J. L. (2014). Climate Change and the Course of Global History: A Rough Journey. Cambridge University Press. pp. 40–42. ISBN 978-0-521-87164-8. 
  334. N. C. Ghose (2017). Prokaryotic micro-fossils in the carbonaceous shale of Gwalior basin of Paleoproterozoic age (2000 Ma Orosirian Period): Primitive life from Central India during Great Oxygenation Event (GOE). 9. Indian Geological Congress. pp. 130-133. Retrieved 28 July 2021. 
  335. David Huddart; Tim Stott (16 April 2013). Earth Environments: Past, Present and Future. John Wiley & Sons. pp. 1599–. ISBN 978-1-118-68812-0. 
  336. El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E.; Riboulleau, Armelle; Rollion Bard, Claire; Macchiarelli, Roberto (2014). "The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity". PLoS ONE 9 (6): e99438. doi:10.1371/journal.pone.0099438. PMID 24963687. 
  337. Experiment Life – the Gabonionta. (Press Release). 4 March 2014. Naturhistorisches Museum Wien
  338. 338.0 338.1 El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E.; Bekker, Andrey; Macchiarelli, Roberto; Mazurier, Arnaud; Hammarlund, Emma U. (2010). "Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago". Nature 466 (7302): 100–104. doi:10.1038/nature09166. PMID 20596019. 
  339. "Une vie complexe il y a 2 milliards d'années : l'hypothèse se confirme !". (in French). 26 June 2014. Retrieved 18 November 2017.
  340. Sebe-Pedros, A.; Roger, A. J.; Lang, F. B.; King, N.; Ruiz-Trillo, I. (2010). "Ancient origin of the integrin-mediated adhesion and signaling machinery". Proceedings of the National Academy of Sciences 107 (22): 10142–10147. doi:10.1073/pnas.1002257107. PMID 20479219. 
  341. "Rhyacian Period". GeoWhen Database. Retrieved January 5, 2006.
  342. James G. Ogg (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia 37 (2): 183–199. doi:10.1080/00241160410006492. 
  343. 343.0 343.1 343.2 Kopp, R. E. ; Kirschvink, J. L. ; Newman, D. K. ; Nash, C. Z. ; Hilburn, I. A. (December 2003). Bacterial Bolsheviks: PS II and the Evolution of the Oxygenic Revolution. American Geophysical Union. pp. U52B-07. Bibcode: 2003AGUFM.U52B..07K. Retrieved 28 July 2021. 
  344. Carolyn M. Hill (28 March 2019). Sedimentology, Lithostratigraphy and Geochronology of the Paleoproterozoic Gordon Lake Formation, Huronian Supergroup, Ontario, Canada, In: Electronic Thesis and Dissertation Repository. 6084. The University of Western Ontario. pp. 234. Retrieved 27 July 2021. 
  345. 345.0 345.1 345.2 345.3 Han, T. M.; Runnegar, B. (1992-07-10). "Megascopic eukaryotic algae from the 2.1-billion-year-old negaunee iron-formation, Michigan". Science 257 (5067): 232–235. doi:10.1126/science.1631544. ISSN 0036-8075. PMID 1631544. 
  346. Schneider, D. A., Bickford, M. E., Cannon, W. F., Schulz, K. J., & Hamilton, M. A. (2002). Age of volcanic rocks and syndepositional iron formations, Marquette Range Supergroup: implications for the tectonic setting of Paleoproterozoic iron formations of the Lake Superior region. Canadian Journal of Earth Sciences, 39(6), 999-1012.
  347. 347.0 347.1 Wang, Y., Wang, Y., & Du, W. (2016). The long-ranging macroalga Grypania spiralis from the Ediacaran Doushantuo Formation, Guizhou, South China. Alcheringa: An Australasian Journal of Palaeontology, 1-10.
  348. James S. Aber (2008). "GLACIATIONS THROUGHOUT EARTH HISTORY". Emporia, Kansas USA: Emporia State University. Retrieved 2014-11-06.
  349. Schneider, D. A., Bickford, M. E., Cannon, W. F., Schulz, K. J., & Hamilton, M. A. (2002). Age of volcanic rocks and syndepositional iron formations, Marquette Range Supergroup: implications for the tectonic setting of Paleoproterozoic iron formations of the Lake Superior region. Canadian Journal of Earth Sciences, 39(6), 999-1012.
  350. 350.0 350.1 350.2 350.3 Dominic Papineau, Stephen J. Mojzsis, and Axel K. Schmitt (6 February 2007). "Multiple sulfur isotopes from Paleoproterozoic Huronian interglacial sediments and the rise of atmospheric oxygen". Earth and Planetary Science Letters 255: 188-212. doi:10.1016/j.epsl.2006.12.015. Retrieved 27 July 2021. 
  351. Kasting, James F.; Ono, Shuehi (2006). "Paleoclimates: The First Two Billion Years". Philosophical Transactions: Biological Sciences 361 (1470): 917–929. doi:10.1098/rstb.2006.1839. PMID 16754607. 
  352. Kopp, Robert E.; Kirschvink, Joseph L.; Hilburn, Isaac A.; Nash, Cody Z. (2005). "The Paleoproterozoic Snowball Earth: A climate disaster triggered by the evolution of oxygenic photosynthesis". PNAS 102 (32): 11131–11136. doi:10.1073/pnas.0504878102. PMID 16061801. 
  353. SemperBlotto (31 May 2005). "Neoarchean". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-02-12. {{cite web}}: |author= has generic name (help)
  354. DCDuring (8 November 2014). "Neoarchean". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-02-12. {{cite web}}: |author= has generic name (help)
  355. Brocks et al. (1999), "Archaean molecular fossils and the early rise of eukaryotes", (Science 285)
  356. Canfield, D (1999), "A Breath of Fresh Air" (Nature 400)
  357. 357.0 357.1 "Mesoarchean". San Francisco, California: Wikimedia Foundation, Inc. 4 November 2014. Retrieved 2015-02-12.
  358. Allwood, Abigail C.; Walter, Malcolm R.; Kamber, Balz S.; Marshall, Craig P.; Burch, Ian W. (8 June 2006). "Stromatolite reef from the Early Archaean era of Australia". Nature 441 (7094): 714–718. doi:10.1038/nature04764. Retrieved 10 March 2018. 
  359. Nelson, Jon (15 April 1997). "Stromatolites: Our Mysterious Ancient Reefs". Lake Superior Magazine. Retrieved 10 March 2018. 
  360. 360.0 360.1 Paleoarchean. San Francisco, California: Wikimedia Foundation, Inc. 4 November 2014. Retrieved 2015-02-12. 
  361. 361.0 361.1 Cavalazzi, Barbara (14 July 2021). "Cellular remains in a ~3.42-billion-year-old subseafloor hydrothermal environment". Science Advances 7 (9). doi:10.1126/sciadv.abf3963. Retrieved 14 July 2021. 
  362. 362.0 362.1 362.2 362.3 362.4 362.5 Dodd, Matthew S.; Papineau, Dominic; Grenne, Tor; slack, John F.; Rittner, Martin; Pirajno, Franco; O'Neil, Jonathan; Little, Crispin T. S. (2 March 2017). "Evidence for early life in Earth's oldest hydrothermal vent precipitates". Nature 543 (7643): 60–64. doi:10.1038/nature21377. PMID 28252057. 
  363. Tyrell, Kelly April (18 December 2017). "Oldest fossils ever found show life on Earth began before 3.5 billion years ago". University of Wisconsin–Madison. Retrieved 18 December 2017.
  364. Schopf, J. William; Kitajima, Kouki; Spicuzza, Michael J.; Kudryavtsev, Anatolly B.; Valley, John W. (2017). "SIMS analyses of the oldest known assemblage of microfossils document their taxon-correlated carbon isotope compositions". Proceedings of the National Academy of Sciences of the United States of America (PNAS) 115 (1): 53–58. doi:10.1073/pnas.1718063115. PMID 29255053. 
  365. SemperBlotto (31 May 2005). Eoarchean. San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-02-12. 
  366. DCDuring (4 November 2014). "Eoarchean". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-02-12. {{cite web}}: |author= has generic name (help)
  367. Ohtomo, Yoko; Kakegawa, Takeshi; Ishida, Akizumi; Nagase, Toshiro; Rosing, Minik T. (January 2014). "Evidence for biogenic graphite in early Archaean Isua metasedimentary rocks". Nature Geoscience 7 (1): 25–28. doi:10.1038/ngeo2025. ISSN 1752-0894. 
  368. Wade, Nicholas (31 August 2016). "World's Oldest Fossils Found in Greenland". The New York Times. Retrieved 31 August 2016.
  369. Allwood, Abigail C. (22 September 2016). "Evidence of life in Earth's oldest rocks". Nature 537 (7621): 500–5021. doi:10.1038/nature19429. PMID 27580031. 
  370. Wei-Haas, Maya (17 October 2018). "'World's oldest fossils' may just be pretty rocks – Analysis of 3.7-billion-year-old outcrops has reignited controversy over when life on Earth began". National Geographic. Retrieved 19 October 2018.
  371. O'Neil, J.; Carlson, R. W.; Francis; D.; Stevenson, R. K. (2008). "Neodymium-142 Evidence for Hadean Mafic Crust". Science 321 (5897): 1828–1831. doi:10.1126/science.1161925. PMID 18818357. 
  372. 372.0 372.1 372.2 Zimmer, Carl (1 March 2017). "Scientists Say Canadian Bacteria Fossils May Be Earth's Oldest". The New York Times. Retrieved 2 March 2017.
  373. 373.0 373.1 SemperBlotto (31 May 2005). "Hadean". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-02-13. {{cite web}}: |author= has generic name (help)
  374. Bell, Elizabeth; Boehnke, Patrick; Harrison, T. Mark; Mao, Wendy L. (24 November 2015). "Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon". Proceedings of the National Academy of Sciences of the United States of America 112 (47): 14518–14521. doi:10.1073/pnas.1517557112. PMID 26483481. 
  375. 375.0 375.1 Ghosh, Pallab (1 March 2017). "Earliest evidence of life on Earth 'found". BBC News. Retrieved 2 March 2017.
  376. 376.0 376.1 Dunham, Will (1 March 2017). "Canadian bacteria-like fossils called oldest evidence of life". Reuters. Retrieved 1 March 2017.
  377. Staff (20 August 2018). "A timescale for the origin and evolution of all of life on Earth". Retrieved 20 August 2018.
  378. Betts, Holly C.; Putick, Mark N.; Clark, James W.; Williams, Tom A.; Donoghue, Philip C.J.; Pisani, Davide (20 August 2018). "Integrated genomic and fossil evidence illuminates life's early evolution and eukaryote origin". Nature 2 (10): 1556–1562. doi:10.1038/s41559-018-0644-x. PMID 30127539. 

External links[edit | edit source]