Eras and periods 
First ''era'' of prehistoric multicellular life is called Proterozoic. 650 million years ago(mya) a mass extinction happened(mass extinction-is a period when many spieces of animals or plants die). After extinction, new spieces named vendobionts appeared. Next 550 mya, after the death of vendobionts, new era begun-Paleozoic. After another mass extinction Mezozoic era started. Now dinosaurs rule. After they became extinct, Cenozoic era begun. People appear.
Main predator:Sea scorpion
Main predator:Armoured fish
Main predator:Giant dragonfly
Main predators:Dinosaurs(see below)
Main predators:Saber-tooth tiger,human.
Dinosaurs are extinct reptiles. They lived from 230 million years ago to 63 million years ago(throughout Triassic, Jurassic and Cretaceous periods).
1818 - In USA was found first dinosaur trackway.In UK bones of Iguanodon are found.
1822 - Megalosaurus is named.
1824 - Iguanodon is named.
Dinosaurs appeared 230 million years ago.Their ancestors were crocodile-like, and walked on 4 legs (they were quadrupedal).Some dinosaurs,howewer, were two-legged (bipedal).
Interesting discoveries 
1968 John Ostrom finds 4 Deinonychus near the Tenontosaurus(Deinonychus is a predator).
1915;1927 The largest land dinosaurs-carnivores are discovered :Spinosaurus(18 metres;20-25 tonns);Carcharodontosaurus(16 metres;8-9 tonns).
- What is the largest dinosaur?Amphicoelias(60 metres)
- What is the smallest dinosaur?Microraptor(30 cm)
- The fastest dinosaur is Dromiceomimus (65kph)
Educational films 
- "Jurassic Fight Club"
- "Walking with dinosaurs"
- "Animal armaggedon'
See also 
- What killed the dinosaurs
- Wikijunior:Dinosaurs (Wikibooks)
- Dinosaur (Wikipedia)
- Dinosaur (Simple Wikipedia)
- Major questions (Wikibooks)