Gorgonopsians were among those animals that did not survive the Permian–Triassic extinction
The Permian-Triassic extinction event, or the end-Permian mass extinction, and popularly known as the Great Dying,[1] was a global catastrophe at the Permian-Triassic (and Paleozoic-Mesozoic) boundary at 251.902 ± 0.024 million years ago. It wiped out 96% of all life on Earth and was the most devastating of all seven mass extinctions in Earth's history.
Prior to extinction[]
Long before the Permian period, the supercontinent Pangea was formed. To the east and northeast of it there were still small areas of land that were gradually approaching. During the Permian, the climate dried out. Inland seas disappeared and reappeared, but the general trend was towards their drying up. Equatorial swampy forests gave way to arid deserts, and Karoo Ice Age continued in the southern hemisphere. Around 260 million years ago, the Capitanian mass extinction occured and around the same time the glaciation ended. Thus, before the Permian-Triassic extinction, a greenhouse climate had already been established on Earth and tectonic processes were taking place that greatly influenced the biota.
Disaster process[]
The last stages of the formation of Pangea were accompanied by active volcanism, and about 252 million years ago, massive outpourings of lava to the surface occurred on the territory of Siberia. The outpourings did not occur from volcanic craters, but directly from trenchs in the earth's crust. Before solidifying, the lava flowed for hundreds of kilometers, which led to the formation of the Siberian traps. According to various estimates, the volume of erupted materials ranged from 1 to 4 million cubic kilometers, which is hundreds of times more than any eruption of the Quaternary period. These eruptions led to warming and an increase in carbon dioxide in the atmosphere, which was only intensified by numerous wildfires in a significantly warmer climate. The extreme amounts of carbon dioxide in the air coupled with clouds of ash dried the surface of the Earth and methane deposits in the ocean suffocated the sea life.
Paleoclimate studies suggest that an important component of the extinction event were El Niño events. Due to the global warming, these events were more intense and longer lasting than El Niños experienced in the 20-21st centuries.[1]
Consequences[]
All blastoid echinoderms, trilobites, and eurypterids were wiped out along with all Acanthodian fish and large amounts of anapsids, synapsids, and diapsids. Lystrosaurus, dicynodonts, survived extinction and became the most common land vertebrates for a short time in the Early Triassic. Small amphibians, reptiles, and therapsids thrived during the early Triassic until the Archosauromorphs, such as dinosaurs and crocodiles, appeared which put the diapsids on top on land and the Mesozoic sea life explosion diversified the diapsids of the seas. Anapsids would never again be as diverse as before the Permian-Triassic extinction event and synapsids would evolve into mammals as time went on.
The final formation of Pangea and global warming subsequently led to reverse processes and the next mass extinction. At the turn of the Triassic and Jurassic periods, the supercontinent began to break, which was again accompanied by active outpourings of lava on the surface, and as a result of the volcanic winter, many animals that had adapted to high temperatures gone extinct.