Geological Periods Blog

The Mesozoic Era (age of reptiles) consisted of three smaller time periods: Triassic, Jurassic, and Cretaceous.
Triassic - this time period was 200-250 million years ago.
organisms: Lystrosaurus, Proterosuchus, Cyognathus, Coelophysis, and Plateosaurus.
~95% of all organisms died out.
This was the era of the first dinosaurs and mammals.


Jurassic - this time period was 150-200 million years ago.
Marine: Pleisosaurs, Gastropod
Land: Stegosaurus, Allosaurus
~80% of all marine organisms died out
During this period, flowers arose and birds started roaming the Earth.


Cretaceous - this time period was 50-150 million years ago.
Marine: Tylosaurus, Woolungasaurus
Land: Tyrannosaurus Rex, Velociraptor, Triceratops
~85% of all species died out.












http://en.wikipedia.org/wiki/Cretaceous
http://en.wikipedia.org/wiki/Jurassic
http://en.wikipedia.org/wiki/Triassic
http://www.enchantedlearning.com/subjects/dinosaurs/mesozoic/