Geologic Timescale

Cambrian Period- 570 – 500 MYA

Feb 10, 1925

first fish. end with an extinction. trilobites are dominant

Ordovician Period- 505 mya

Feb 10, 1936

animals with backbones appear 500my. under water

Silurian Period-438 mya

Feb 10, 1943

first land plants. first jawed fishes. first insects

Devonian Period-408 mya

Feb 10, 1952

first amphibians. fist tetrapds. ends with an extinction

Carboniferous Period-360 mya

Feb 10, 1963

first reptiles. coal-forming swamps

Permian Period-286 mya

Feb 10, 1973

formation of Appalachians then Pangaea forms. Permian ends with MASS extinction

Triassic Period- 245 mya

Feb 10, 1978

first dinosaurs, Pangaea cracks 200my, then first mammals

Jurassic Period- 208 mya

Feb 12, 1988

first birds. S. America & Africa split. Watchung Mts. first mammals.

Cretaceous Period-144 mya

Feb 12, 2001

modern look to world. rockies form. then Dino extinct. India broke off.

Tertiary Period- 66 - 5.3 mya

Feb 12, 2012

First large mammals. Alps then Himalayas as india crashes. Modern-looking Earth 40 my

Quaternary Period- 1.6 - .01 mya

Feb 12, 2013

Earliest Humans, then ice age. ice age creates lakes such as Yosemite