Ok I don't know if I'm doing this right, but instead of having to go to blackboard and re-reading that article on mass extinctions, I guess I'll just put the big 5 right here:
Cretaceous-Paleogene (65 MYA):
-60% of all life extinct
-caused by asteroid impact near Mexico
-dinosaurs major group that died
-Birds + mammals took off
Triassic-Jurassic (200 MYA)
-76% of all life extinct
-caused by volcanism associated with the Pangea breakup; sea-levels rising; climate drying; potential asteroid collisions
-Conodonts died out
-dinosaurs took off
Permian-Triassic (252 MYA)
-90% of marine life, 70% of vertebrates died
-caused by Siberian volcano launching sulfur dioxide into the atmosphere causing acid rain to form sulfuric acid in the waters
-Trilobites died out
-Bivalves took off
Late Devonian (376 MYA)
-70-82% of all species died out
-caused by potential global cooling caused by volcanism; asteroid collisions; low "oceanic oxygen levels"
-coral reef systems died out
-Hexactinellids (glass sponges) took off
Late Ordovician (445 MYA)
-85% of all species
-caused by potential rapid retreat of glaciers; sea level changes; global circulation
-NO MAJOR GROUPS WENT EXTINCT
-Brachiopods and Crinoids took off
I hope I did this right and apologies for the weird font and boldness and italics. This is confusing.
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This looks great! Is the assignment confusing or the logisitics of posting?
ReplyDeletethis was really helpful!! thanks!
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