Permian–Triassic extinction event
Approximately 251.9 million years ago, the Permian–Triassic extinction event forms the boundary between the Permian and Triassic geologic periods, and with them the Paleozoic and Mesozoic eras. It is the Earth's most severe known extinction event, with the extinction of 57% of biological families, 83% of genera, 81% of marine species and 70% of terrestrial vertebrate species. It is also the greatest known mass extinction of insects. It is the greatest of the "Big Five" mass extinctions of the Phanerozoic. There is evidence for one to three distinct pulses, or phases, of extinction.
Permian–Triassic boundary at Frazer Beach in New South Wales, with the End Permian extinction event located just above the coal layer
Shell bed with the bivalve Claraia clarai, a common early Triassic disaster taxon
Sessile filter feeders like this Carboniferous crinoid, the mushroom crinoid (Agaricocrinus americanus), were significantly less abundant after the P–Tr extinction.
Lystrosaurus was by far the most abundant early Triassic land vertebrate.
The Permian is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia.
Selwyn Rock, South Australia, an exhumed glacial pavement of Permian age
Hercosestria cribrosa, a reef-forming productid brachiopod (Middle Permian, Glass Mountains, Texas)
Fossil and life restoration of Permocupes sojanensis, a permocupedid beetle from the Middle Permian of Russia
Edaphosaurus pogonias and Platyhystrix – Early Permian, North America and Europe
