Mass Extinction

Ordivician mass extinction

440

occured 440-450 Ma
secondmost devastating extinction
2/3 of all life ceased to exist in oceans and seas
caused by glaciation of Gondwana which lowered the sea level globally(global cooling)

Permian Mass extinction

Nov 8, 650

252.28 Ma
known as the Great Dying
-96% all marine species
-70% of terrestitrial vertebrate
-57% of all families and 83% of all genera became extinct
-due to the massive loss of biodiversity, recovery of life on Earth took significantly longer than any other extinction event: 10 million years
-3 phases of extinction from gradual environment change:
asteroid, volcanism, methane hydrate gasification, sea level fluctuations, anoxia, hydrogen sulfide emissions, super continent of Pangaea

Triassic

Nov 8, 700

-occurred 201.3 million years ago
-20% of all marine families disappeared. On land, all large crurotarsans (non-dinosaurian archosaurs) other than crocodilians, some remaining therapsids, and many of the large amphibians were wiped out.
-Theories as to how it happened:
climate change, asteroid impact, massive volcanic eruptions

Devonian

Mar 2, 2022

The Devonian period ranged from 408-360 million years ago. Mass extinction occured in Devonian by a metorite that impacted at the Frasian boundary. Devonian also included insects, plants, and also forests. 19% of families and 50% of genera were wiped out which means the total is 70% together were wiped out from the extinction.

Cretaceous Mass Extinction

Mar 2, 2022

-Occurred 66 million years ago.
-three quarters of plant and animal species on Earth -including all non-avian dinosaurs- 75% or more of all species were wiped out by the K–Pg extinction
-K-Pg event
-Evidence of extinction: Chicxulub crater in the Gulf of Mexico