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.
Reptiliomorpha is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians). It was defined by Michel Laurin (2001) and Vallin and Laurin (2004) as the largest clade that includes Homo sapiens, but not Ascaphus truei. Laurin and Reisz (2020) defined Pan-Amniota as the largest total clade containing Homo sapiens, but not Pipa pipa, Caecilia tentaculata, and Siren lacertina.
In the geologic timescale, the Wuchiapingian or Wujiapingian is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or Series. The Wuchiapingian spans the time between 259.51 and 254.14 million years ago (Ma). It was preceded by the Capitanian and followed by the Changhsingian.
In the geologic time scale, the Changhsingian or Changxingian is the latest age or uppermost stage of the Permian. It is also the upper or latest of two subdivisions of the Lopingian Epoch or Series. The Changhsingian lasted from 254.14 to 251.9 Ma ago. It is preceded by the Wuchiapingian age/stage and is followed by the Induan age/stage.
Hovasaurus is an extinct genus of basal diapsid reptile. It lived in what is now Madagascar during the Late Permian and Early Triassic, being a survivor of the Permian–Triassic extinction event and the paleontologically youngest member of the Tangasauridae. Fossils have been found in the Permian Lower and Triassic Middle Sakamena Formations of the Sakamena Group, where it is amongst the commonest fossils. Its morphology suggests an aquatic ecology.
Embolomeri is an order of tetrapods or stem-tetrapods, possibly members of Reptiliomorpha. Embolomeres first evolved in the Early Carboniferous (Mississippian) Period and were the largest and most successful predatory tetrapods of the Late Carboniferous (Pennsylvanian) Period. They were specialized semiaquatic predators with long bodies for eel-like undulatory swimming. Embolomeres are characterized by their vertebral centra, which are formed by two cylindrical segments, the pleurocentrum at the rear and intercentrum at the front. These segments are equal in size. Most other tetrapods have pleurocentra and intercentra which are drastically different in size and shape.
Archeria is a genus of embolomere which lived in the Early Permian of Texas and Oklahoma. It was a medium-sized aquatic predator, with an elongated body and tail. The limbs were proportionally small but well-developed, connected to robust limb girdles. The skull was moderately long and low, up to 30 cm in length. Unlike most embolomeres, Archeria had many small chisel-shaped teeth instead of large fangs.
Diplovertebron is an extinct genus of embolomere that lived in the Late Carboniferous period (Moscovian), about 310 million years ago. Diplovertebron was a medium-sized animal, around 50 cm in length. Members of the genus inhabited European Carboniferous swamps in what is now the Czech Republic. They were closely related to larger swamp-dwelling tetrapods like Proterogyrinus and Anthracosaurus. However, Diplovertebron were much smaller than these large, crocodile-like creatures. Known from a single species, Diplovertebron punctatum, this genus has had a complicated history closely tied to Gephyrostegus, another genus of small, reptile-like amphibians.
Archegosaurus is a genus of temnospondyl amphibian which lived during the Asselian to Wuchiapingian stages of the Permian, around 299-253 million years ago. The remains of this animal, consisting of at least 90 partial skeletons, have been found in Germany. The name Archegosaurus was coined by Goldfuss in 1847. Archegosaurus is a member of Archegosauridae and is that family's type genus.
Neopteroplax is an extinct genus of eogyrinid embolomere closely related to European genera such as Eogyrinus and Pteroplax. Members of this genus were among the largest embolomeres in North America. Neopteroplax is primarily known from a large skull found in Ohio, although fragmentary embolomere fossils from Texas and New Mexico have also been tentatively referred to the genus. Despite its similarities to specific European embolomeres, it can be distinguished from them due to a small number of skull and jaw features, most notably a lower surangular at the upper rear portion of the lower jaw.
Shihtienfenia was a pareiasaurid parareptile from the Late Permian of China.
Ambedus is an extinct genus of possible diadectid reptiliomorph. Fossils have been found from the Early Permian Dunkard Group of Monroe County, Ohio. The type species A. pusillus was named in 2004. The genus name comes from the Latin word ambedo meaning "to nibble", in reference to its herbivorous diet. The specific name pusillus means "tiny" in Latin.
Alveusdectes is an extinct genus of diadectid tetrapod from the Late Permian of China. Like other diadectids, it was a large-bodied terrestrial herbivore capable of eating tough fibrous plant material. It was described in 2015 on the basis of a single partial skull and lower jaw found in the Shangshihezi Formation near the city of Jiyuan in Henan. This skull was found in a layer of the Shangshihezi Formation that dates to about 256 million years ago and contains the remains of many other terrestrial tetrapods including pareiasaurs, chroniosuchians, and therapsids. Alveusdectes is the youngest known diadectid by 16 million years and is also the only diadectid known from Asia. It likely represents a late-surviving lineage of diadectids that radiated eastward from western Laurasia into north China. Diadectids are otherwise absent from eastern Laurasia, which may reflect their low diversity at the time. Diadectids first appeared in the Late Carboniferous and were the first animals to have ever occupied the niche of large-bodied herbivores, allowing them to undergo an evolutionary radiation in the Early Permian. By the Late Permian many other groups of tetrapods had entered that niche, and increased competition among herbivores likely resulted in the eventual extinction of diadectids. Alveusdectes may have been able to persist because the fauna of north China seems to have been isolated from other Laurasian faunas during the Late Permian, meaning that fewer herbivores were competing for the same ecological space.
Counillonia is an extinct genus of dicynodont therapsid from the area of Luang Prabang in Laos, Southeast Asia that lived at around the time of the Permian-Triassic boundary and possibly dates to the earliest Early Triassic. Its type and only known species is C. superoculis. Counillonia was related to the Triassic dicynodonts such as Lystrosaurus and the Kannemeyeriiformes that survived the Permian mass extinction, but it was more closely related to the Permian genus Dicynodon than to either of these lineages. Counillonia may then possibly represent another line of dicynodonts that survived the Permian mass extinction into the Triassic period, depending on its age. The discovery of Counillonia in Laos and its unexpected evolutionary relationships hint at the less well understood geographies of dicynodont diversity across the Permo-Triassic boundary outside of well explored regions like the Karoo Basin in South Africa.
Taoheodon is an extinct genus of dicynodont therapsid from the Sunjiagou Formation in the Shanxi province of China, dated to the Wuchiapingian age of the Late Permian. Its type and only known species is T. baizhijuni. Taoheodon was a close relative of the well known Dicynodon, and may represent a biogeographical link between the South African Dicynodon and similar dicynodonts found in Laos.
The Sunjiagou Formation is a geological formation in Shanxi, China. It is of Lopingian age. The lower and middle parts of the formation consists of intensely bioturbated fine grained sandstones and thinly interbedded mudstones, deposited in a shallow-shore lake depositional environment, while the upper part consists of fine grained sandstone, siltstone and mudstone. Alongside the Naobaogou Formation, it has provided an important vertebrate fauna.
This list of fossil amphibians described in 2020 is a list of new taxa of fossil amphibians that were described during the year 2020, as well as other significant discoveries and events related to amphibian paleontology that occurred in 2020.
Aversor is an extinct genus of embolomere which lived in the Early Permian of Russia. It contains a single species, Aversor dmitrievi, which is based on skull and jaw fragments from the Intinskaya Svita near Pechora. It may have been the youngest known eogyrinid, and was the youngest known embolomere until the discovery of Seroherpeton, a Late Permian embolomere described in 2020. Aversor and Seroherpeton both lived at higher latitudes than older embolomeres, suggesting that the group abandoned arid equatorial areas prior to their final demise.
Eobaphetes is an extinct genus of embolomere which likely lived in the Pennsylvanian of Kansas. The genus is based on several skull and jaw fragments of a single individual. They were originally described under the species Erpetosuchus kansasensis, but this was later changed to Eobaphetes kansasensis when it was determined that Erpetosuchus was preoccupied by a Triassic reptile.
Sanchuansaurus is an extinct genus of pareiasaur from the late Permian Sunjiagou Formation of China. The genus contains a single species, S. pygmaeus, known from a partial maxilla and left leg bones. A 2013 study suggested that both Sanchuansaurus and another Chinese pareiasaur, Huanghesaurus, were synonymous with Shansisaurus. However, this has not been followed in future research, with later papers considering Sanchuansaurus to be distinct, with Huanghesaurus and Shansisaurus possibly being synonymous with Shihtienfenia, another Chinese pareiasaur.
