Phanerozoic/Cambrian period

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Kenneth Sobieski This page is under construction

General[edit]

Adam Sedgwick (1758-1873)

The Cambrian Period, named for a sparsly fossiliferous sequence of rocks in Wales(Latin name: Cambria) occurred between 542 Million Years Ago (MYA) and 488 MYA. The system was named by Adam Sedgwick, a Geology professor at Cambridge University, in the 1830s.[1]











Climate[edit]

The Cambrian world was bracketed between two ice ages, one during the late Late Proterozoic and the other during the Ordovician. During these ice ages, the decrease in global temperature led to mass extinctions. Cooler conditions eliminated many warm water species, and glaciation lowered global sea level. However, during the Cambrian there was no significant ice formation. None of the continents were located at the poles, and so land temperatures remained mild. In fact, global climate was probably warmer and more unifrom than it is today. With the beginning of the Cambrian at the retreat of Proterozoic ice, the sea level rose significantly. Lowland areas such as Baltica were flooded and much of the world was covered by epeiric seas. This event opened up new habitats where marine invertebrates, such as the trilobites, radiated and flourished. [2]

Land Mass Configuration[edit]

Breakup of Rodinia into:

  • Gondwana (today's southern continents)
  • Laurentia (most of North America)
  • Siberia
  • Baltica








Intra-Cambrian Periods[edit]

Russian-Kazakhian Stages

  • Batyrbayan (491.5 - 488)
  • Aksayan (493 - 491.5)
  • Sakian (494.5 - 493)
  • Ayusokkanian (501 - 494.5)
  • Mayan (502-501)
  • Amgan (513 - 502)
  • Toyonian (518.5 - 513)
  • Botomian (524 - 518.5)
  • Atdabanian (530 - 524)
  • Tommotian (534 - 530)
  • Nemakit-Daldynian (542 - 534)


Regional Stages

  • Dolgellian (492.5 - 488)
  • Festiniogian (496.8 - 492.5)
  • Maentwrogian (501 - 496.8)
  • Lenian (524 - 513)


North American Stages

  • Sunwaptan (493MYA To 491MYA)
  • Steptoan (494.5MYA To 493MYA)
  • Marjuman (504 To 494.5 Ma)
  • Delamaran (512MYA To 504MYA)
  • Dyeran (524.5MYA To 512MYA)
  • Montezuman (529.5MYA To 524.5MYA)


Australian Stages

  • Payntonian (491 - 488)
  • Idamean (497 - 494)
  • Mindyallan (501-497)
  • Boomerangian (504-501)
  • Undillian (506-504)
  • Florian (508-506)
  • Templetonian (510-508)
  • Ordian (520 - 510)


Chinese Stages

  • Zhungxian (505 - 501)
  • Zuzhuangian (509-505)
  • Maozhangian (513 - 509)
  • Longwangmioan (518-513)
  • Changlangpuan (523-518)
  • Qungzusian (532 - 523)
  • Meishuchuan (542 +/- 0.3 To 532 Ma)


  MYA Russian-Kazakhian Stage Regional Stage North American Stage Australian Stage Chinese Stage
LATE CAMBRIAN (501MYA - 488MYA) 488 Batyrbayan (491.5 - 488) Dolgellian (492.5 - 488)   Payntonian (491 - 488.3)  
488.5    
489    
489.5    
490    
490.5    
491 Sunwaptan
(493MYA To 491MYA)
 
491.5    
492 Aksayan
(493 - 491.5)
   
492.5    
493 Sakian
(494.5 - 493)
Festiniogian (496.8 - 492.5)    
493.5 Steptoan
(494.5MYA To 493MYA)
   
494 Idamean (497 - 494)  
494.5 Ayusokkanian (501 - 494.5)  
495 Marjuman (504 To 494.5 Ma)  
495.5  
496  
496.5  
497  
497.5 Maentwrogian (501 - 496.8) Mindyallan (501-497)  
498  
498.5  
499  
499.5  
500  
500.5  
501 Mayan
(502-501)
Zhungxian (505 - 501)
MIDDLE CAMBRIAN (513MYA - 501MYA) 501.5   Boomerangian (504-501)
502 Amgan (513 - 502)  
502.5  
503  
503.5  
504  
504.5   Delamaran (512MYA To 504MYA) Undillian
(506-504)
505  
505.5   Zuzhuangian (509-505)
506  
506.5   Florian
(508-506)
507  
507.5  
508  
508.5   Templetonian
(510-508)
509   Maozhangian (513 - 509)
509.5  
510   Ordian (520 - 510)
510.5  
511  
511.5  
512  
512.5   Dyeran (524.5MYA To 512MYA)
513 Lenian (524 - 513)
513.5 Toyonian (518.5 - 513) Longwangmioan (518-513)
EARLY CAMBRIAN (542MYA - 513MYA) 514
514.5
515
515.5
516
516.5
517
517.5
518
518.5 Botomian (524 - 518.5) Changlangpuan (523-518)
519
519.5
520
520.5  
521  
521.5  
522  
522.5  
523   Qungzusian (532 - 523)
523.5  
524  
524.5 Atdabanian (530 - 524)    
525   Montezuman (529.5MYA To 524.5MYA)  
525.5    
526    
526.5    
527    
527.5    
528    
528.5    
529    
529.5    
530      
530.5 Tommotian (534 - 530)      
531      
531.5      
532   v  
532.5       Meishuchuan (542 +/- 0.3 To 532 Ma)
533      
533.5      
534      
534.5 Nemakit-Daldynian (542 - 534)
     
535      
535.5      
536      
536.5      
537      
537.5      
538      
538.5      
539      
539.5      
540      
540.5      
541      
541.5      
542      
             

Stratigraphy[edit]

On of the most famous stratigraphic formations is the Burgess Shale in what is now British Columbia's Yoho National Park, in an area of the Canadian Rocky Mountains known as the Burgess Pass.

Flora and Fauna: The Cambrian Explosion[edit]

With the breakup of Rodinia, and the melting of glaciers, the world gained much more warm, shallow, oxygen-rich coastlines which life could exploit. The favorable climate lead to what is popularly known as "The Cambrian Explosion." The Cambrian Explosion seems, in fact, to have been an "arms race" between the predators and the prey, which may also help to explain the diversity.

Land Animals

  • NONE


Sea Animals

  • Invertibrates
    • Aysheaia pedunculata
    • Hallucigenia
    • Anomalocaris
    • Opabinia
    • Wiwaxia
    • Arthropods
      • trilobites
        • most abundant and diverse animals of Cambrian time
        • long antennae, compound eyes, many jointed legs, and a hard exoskeleton
        • ranged from a few millimeters (1 mm = 0.25 inches) to 45 centimeters (18 inches).
    • archaeocyathids
    • hyoliths
    • monoplacophorans
    • inarticulate brachiopods
    • primitive echinoderms
    • articulate brachiopods
    • stony and lacy bryozoans
    • stromatoporoids
    • cephalopods
    • crinoids and blastoids
    • starfish
    • graptolites
    • bivalves
    • gastropods
    • vertebrates
    • echinoids
    • crustaceans
    • gymnolaemate bryozoans


  • Vertibrates
    • Haikouichthys


Land Plants

  • NONE


Sea Plants

  • Single-Celled
    • Algaes
    • Fungi (molds, mushrooms, and yeasts)
    • lichens (cooperation between fungi and algae to form a single-organism partnership)
    • mosses


  • Multi-Celled
    • None

References[edit]

  1. The Earth Through Time, 8th ed., Harold Levin
  2. http://www.ucmp.berkeley.edu/cambrian/cambtect.html