Mass Extinctions

Period	Time	Length of Extinction	% Life Extinct	Groups Affected	Cause
	11000 ya		2/3 North American Mammals	Mammals	Climate change Man
End Cretaceous	65 mya		85% all species	Dinosaurs Pterasaurus Mosasaurs Fish Brachipods Plankton Plants Ammonites disappeared	Meteroite Volcanic Activity Climate change
Late Triassic			25% all families	Sponges Cephalopods Brachiopods Insects Vert. Groups Conodonts dissappeared completely	Climate Change Increase rainfall
End Permian	245 mya		96% Marine species 75% Land Vertebrates		Sea Level Ocean salinity Volcanic activity Climate change
Late Devonian	365 mya	3 million	70 %	Brachiopods Ammonites Agnathan & Placoderm Fish	Climate Change Global coolong Drop in Oxygen
Late Ordovician	440 mya	10 million	100 families marine invertebrates	Echinoderms Trilobites Nautiloids	Glaciation Ice Age Seas retreated Seas rose rapidly
Late Cambrian	500 mya			Brachiopods Condonts Trilobites	Change in sea level Lack oxygen