Life & Evolution

Claire Morgan

Knowledge Exchange

09-10-2011

Earths History

Paleozoic Era: Cambrian

Paleozoic Era: Ordovican

Brachiopods

Mollusks

MASS EXTINCTION~75% of species extinct

•Sea levels droped ~50 meters

•Ocean temperatures dropped

•Glaciers formed over Godwana

Paleozoic Era: Silurian

Cooksonia MillipedesScorpion

Ray-finned fish

Paleozoic Era: Devonian

MASS EXTINCTION~75% of species extinct

•Jawed Fish replaced Jawless Fish•Mosses + Ferns evolved on land•First Centipedes, Spiders, Mites and Insects•Fish like amphibians start to occupy the land

Two Meteorites collided with out planet

(1) Current day Nevada(2) Current day western Australia

Paleozoic Era: Carboniferous

•Giant tree ferns dominated land•Insects evolved wings•Amphibians became larger•First reptiles evolved

•Crinoids (sea lillies and stars)•Meadows on sea floor

Paleozoic Era: Permian

Theraspid

MASS EXTINCTION~96% of species extinct

•Large meteorite crashed into Northwestern Australia

•Lava poured into oceans reducing O2 content.

•Toxic concentrations of CO2 and H2S

Mesozoic Era: Triassic

MASS EXTINCTION~65% of species extinct

•Reptiles Dominated the Mesozoic Era•Rise of Crocodilians, Dinosaurs and Birds•First frogs and turtles appeared•Conifers and seed ferns were dominant trees

•Meteor crashed into modern day Quebec

Mesozoic Era: Jurassic

•Salamanders and lizards appear•Flying reptiles (pterosaurs)•Bipedal predators and Quadruple herbivores•Emergence of Flowering plants•First birds appear

Mesozoic Era: Cretaceous

MASS EXTINCTION~76% of species extinct

•Meteorite crashes into Yucatan pennusila•Known as K-T impcact•Dinosaurs were wiped out

Cenozoic: Tertiary

Cenozoic: Quaternary(Present period)

Conclusion

•Life Began 3.8 bya

•Cambrian Explosion 534 mya

•There have bee 5 Mass Extinctions on our Planet

•99% of all species on our planet have gone extinct

75% 75% 96% 65% 76%

Thank you…..Questions?