The Permian era lasted 48 million years, beginning with a glaciation age and ending with the End-Permian extinction, which wiped out 95% of marine genera and 70% of terrestrial genera. Pangea formed during this era, making the interior of the supercontinent extremely dry. The era saw great evolution for land animals, including the first major diversification of amniote tetrapods, competition between reptiles and ancestors of mammals, and the evolution of archosaurs. Most animals died at the end of the Permian, leaving only a few survivors.
Permian organisms lived during the Permian era, which lasted from about 299 to 251 million years ago, with a total length of about 48 million years. The period opened with a glaciation age similar to the relatively recent ice ages of modern geological times, then warmed midway through the period. Sea levels rose as a result, producing large, marine-friendly continental seas. The era ended with the most severe mass extinction in the history of life, the End-Permian extinction, which wiped out 95% of marine genera and 70% of terrestrial genera. It was also the last period of the Paleozoic era.
The supercontinent of Pangea formed during this era, enclosing all of the world’s landmasses except for a microcontinent about half the size of Australia called South China. This large landmass made the interior of the supercontinent extremely dry, while land animals spread everywhere. The continent of Pangea straddled the equator and had a rough C shape.
The marine invertebrates of the time were mostly extensions of lineages originating in the immediately preceding middle and late Carboniferous period. These included the ubiquitous brachiopods, bryozoans, echinoderms, molluscs, corals, ammonioids, and others. Only a group of trilobites survived until this period, only to become extinct at its conclusion. Marine vertebrates included numerous fish, sharks, conodonts, and other animals that evolved during the Devonian, Carboniferous, and Cambrian respectively. The euryptids, huge sea scorpions that dominated the seabed throughout almost the entire Paleozoic, became definitively extinct at the end of the Permian.
In terms of terrestrial life, this time period was filled with rapid evolution and change. Marsh lycopods, a genus of mosses, were replaced by conifers, which could better adapt to the changing climate and had superior defenses against newly evolved terrestrial herbivores.
The Permian was a time of great evolution for land animals. Insects diversified from their primitive state during the Carboniferous, producing many groups we find familiar today, such as scorpionfish, dragonflies, true bugs, wasps, and many others. The era has been called the greatest period of all time for insect diversification.
It also saw the first major diversification of amniote, or non-amphibian, tetrapods, including competition between sauropsids, or reptiles, and synapsids, the ancestors of mammals. While there were many large amphibians during this period, they were joined by other large tetrapods, most notably the pelycosaurs, a sauropsid that had evolved in the late Carboniferous and had its heyday during this period. In the later part of the era, the first archosaurs evolved, which would later give rise to the dinosaurs that would dominate the Mesozoic.
In the middle of the era, primitive therapsids, an ancestor of mammals, such as Dinocephaly evolved, and in the Late Permian, more advanced therapsids such as gorgonopsids and dicynodonts evolved. Therapsids ranged in size from small rats to oxen or bear-sized animals, while pelycosaurs were usually large in size, between about 1 m (3.2 ft) and 4 m (13 ft).
By the end of the Permian, most animals of all kinds died, and evolution had to start anew with the few remaining survivors, most notably the pig-sized herbivorous therapsid Lystrosaurus.
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