30.3/30.4 THE MESOZOIC (MIDDLE AND RECENT HISTORY)

MESOZOIC

Main factors of the Mesozoic Milder climate Oceans were 10 degrees or warmer Evidence suggest that there was no glacial

ice at the poles. Dinosaurs dominated and went extinct (hey,

heey HEY, HEEEY H, H HEEY, H, H Hey, Heeey)

Appearance of new ssp.

MESOZOIC

Triassic Period Lasted from 248

mil - 206 mya Ammonites

(Cephalopods) are important index fossils. Went extinct by the end of the period.

Plants included Tree ferns, Spore

bearing ferns and rushes

MESOZOIC

TriassicMost of the Triassic, land

was joined in one supercontinent. Then eventually broke up.

Pangea (all continents joined) The northern part,

Laurasia contained what is now N. America and Eurasia.

The rest of the continents started out as the continent Gondwanaland.

MESOZOICJurassic 206-144 mya Many types of dinos appeared The famous Archeaopteryx and

Protoavis Transition fossil for birds

The appearance of the first true mammals.

Cycads and conifers were abundant.

Some present day bodies of water formed The North and south Atlantic

MESOZOIC

Cretaceous 144-65mya Dinos often exceeded 25m Appearance of flowering plants Rocky Mnt Oregeny and re-elevation of the

Appalachians Mass extinction

50% of plants and animals went extinct Large asteroid struck 65 mya sending dust into the

atmosphere. Struck near present day Yucatan Peninsula Carcharodontosaurus was probably largest meat

eater.

EARTH RECENT HISTORY

The Cenozoic Era Started 65mya Most recent era Rise of the mammals Modern plants evolve Climate was warm and humid Continents came to present day position Rise of the hominids (bipeds) bout 2-3my on earth.

Australopithecus oldest Homo Habilus (tools) 1.5-2 mya Homo Erectus 1.5 mya Homo Sapiens twice 300,000-400,000 ya