End Permian Extinction
Major Paleozoic extinction events
Late Ordovician
Fransian-Fammenian (Late Devonian)
End Permian
Mass extinctions:
>40% of existing genera go extinct
Extinction occurs in a short time interval
Occurs in many phyla
Ordovician
Increase in oxygen isotopes, disappearance of tropical reef builders
Though to be caused by glaciation and global cooling
Devonian
Increase in oxygen isotopes
Increased photosynthesis by plants (invading the land at this time)
Caused decrease in CO2 in the atm.
Global cooling
End Permian
2 pulses, over 80% of all genera extinct
Rugose and tabulate corals
Trilobites
Most Therapsids
Many foraminifera
Many Ammonoids
Many Brachiopods
Deposition of black shales (anoxic basin situation)
Widespread marine regression=drying out of continents and loss of ecological
niches
Volcanism (Siberian Traps and S. China) CO2 and SO2 global warming
Change in salinity in the oceans? (many evaporate deposits)
Shutting down of ocean circulation = anoxic basin = death to marine organisms
Extraterrestrial impact?