The Permian-Triassic Extinction

Georgios Kepertis

Earth 102-6: Death of the Dinosaurs

Paper 4: Permian-Triassic Extinction

12-7-2015

The Permian-Triassic Extinction Event: When Life on Earth Almost Ended

An event that marked a great transition, an event so overwhelming that most creatures on Earth could not handle it; its power so immense that even plants and insects were almost eradicated from the face our planet. If it were to happen today, humans would most certainly be defenseless against the brute forces of nature, and even though it happened roughly 252 million years ago, it is still the most catastrophic period in time known to man. Colloquially known as the “Great Dying”, its scientific name is not quite as terrifying, “The Permian-Triassic Extinction Event”. As

Some “abnormal gymnosperm pollen grains” found in China and Russia, which date to the late Permian, imply severe deterioration in global climate and atmospheric conditions (Foster and Afonin, 2005). A very interesting observation associated with the extinction of plants during that period is what is known as the “Coal gap”. The Coal gap is the phenomenon of absence of coal deposits in the Early Triassic and the very rare and thin deposits during the Middle Triassic. There have been many possible explanations for the Coal gap, such as tectonic movement, climate, and fungal decomposers but the most likely reason for it is the extinction of “peat-forming plants” during the Permian Triassic boundary and the fact that it took another 10 million years for new peat-forming plants to evolve since the soil conditions were very different than those in the Permian Period (Retallack et al.,

It has been found that about 8-9 orders of insects went extinct as a direct result of the event, since the highest extinction rates can be traced very close to the Permian-Triassic boundary (Erwin, 1994). Most of the fossils found after the major extinction occurred differ greatly from the more primitive insects of the Permian. The orders that survive today show very strong diversifications during the periods that followed the Permian, especially the Late Triassic and Early Jurassic. The diversity has been steadily increasing ever since (Labandeira and Sepkoski, 1993). Something interesting about a different type of invertebrates, the Gastropods, is that there appear to be many Lazarus taxa. What this means is that these taxa seem to disappear from the fossil record right after the extinction event but then after a prolonged time period they seem to reappear (Jablonski et al.,