Permian–Triassic Extinction Event
The Permian–Triassic (P–Tr) extinction event, informally known as the Great Dying, was an extinction event that occurred 252.28 Ma (million years) ago, forming the boundary between the Permian and Triassic geologic periods, as well as the Paleozoic and Mesozoic eras. It is the Earth's most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct. It is the only known mass extinction of insects. Some 57% of all families and 83% of all genera became extinct. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after any other extinction event, possibly up to 10 million years.
Researchers have variously suggested that there were from one to three distinct pulses, or phases, of extinction. There are several proposed mechanisms for the extinctions; the earlier phase was likely due to gradual environmental change, while the latter phase has been argued to be due to a catastrophic event. Suggested mechanisms for the latter include large or multiple bolide impact events, increased volcanism, coal/gas fires and explosions from the Siberian Traps, and sudden release of methane clathrate from the sea floor; gradual changes include sea-level change, anoxia, increasing aridity, and a shift in ocean circulation driven by climate change.
Other articles related to "extinction event, extinction, event, events":
... The Permian ended with the most extensive extinction event recorded in paleontology the Permian-Triassic extinction event ... It is also the only known mass extinction of insects ... Recovery from the Permian-Triassic extinction event was protracted on land, ecosystems took 30M years to recover ...
... The resultant global warming may have caused perhaps the most severe anoxic event in the oceans' history according to this theory, the oceans became so anoxic that ... However, there may be some weak links in this chain of events the changes in the 13C/12C ratio expected to result from a massive release of methane do not match the patterns seen throughout the early ...
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