Geologic Time Scales

Geologic Time
Paleozoic Era
Cambrian Period
Ordovician Period
Silurian Period
Devonian Period
Carboniferous Period
Mesozoic Era
Triassic Period
Jurassic Period
Cretaceous Period
Cenozoic Era
Tertiary Period
Quaternary Period
Geologic Timeline

Web Sites

Paleozoic Era. UC Berkeley

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Geologic Time Scales

Jurassic Period

Dating from 208-146mya, the Jurassic Period saw the dinosaurs become the dominant land animals on Earth. During this time, bony fish dominated the seas, and the first mammal evolved. Herbivorous dinosaurs put more pressure on the dominant land plant, gymnosperms, pushing them to new strategies to survive this predator. During the Jurassic, a group of Theropods developed feathers, possibly as a defense against the cold in a similar manner to fur in mammals. This group of Theropods eventually gave rise to the first birds, who outlived the dinosaurs.