Permian synapsids

Mesenosaurus is an extinct genus of synapsid belonging to the family Varanopidae. This genus includes two species: the type species Mesenosaurus romeri from the middle Permian (upper Kazanian) Mezen River Basin of northern Russia, and Mesenosaurus efremovi from the early Permian (Artinskian) Richards Spur locality (Oklahoma, United States). M. romeri’s stratigraphic range is the middle to late Guadalupian while M. efremovi’s stratigraphic range is the Cisuralian.

Lystrosauridae is a family of dicynodont therapsids from the Permian and Triassic time periods. It includes two genera, Lystrosaurus and Kwazulusaurus. Kwazulusaurus includes a single species, K. shakai, from the Late Permian of South Africa and Lystrosaurus includes many species from the Late Permian and Early Triassic of South Africa, India, and Antarctica.

thumb|left|Galepus jouberti fossil, specimen 5541 thumb|left|Galepus jouberti skull restoration, specimen 5541

thumb|left|Life restoration Scylacosaurus is an extinct genus of therocephalian therapsids that lived during the Permian period. It contains one species Scylacosaurus sclateri.

Geikiidae is a family of Late Permian dicynodonts. Fossils are known from Scotland, South Africa, and Tanzania. The family was first named by Franz Nopcsa in 1923, although Friedrich von Huene's 1948 description of the family brought it into common usage. Von Huene established Geikiidae as a monotypic family for Geikia, then known from Scotland. He distinguished Geikia from all other dicynodonts because it lacked a preparietal bone. The outlines on the bones of the skull roof could not be seen however, meaning that this characteristic was uncertain in geikiids. Geikiids were originally classif

Lycosuchidae is a family of therocephalians (an extinct type of therapsids, broader group which modern mammals belong to) known from fossils from what is now the Beaufort Group of South Africa and that lived during the Middle to Late Permian between roughly 265 to 259.2 million years ago. It currently includes only two genera each with a single species, Lycosuchus, represented by L. vanderrieti, and Simorhinella, represented by S. baini, both named by paleontologist Robert Broom in 1903 and 1915, respectively (though Simorhinella was not recognised as a lycosuchid until 2014). Both species are

Chainosauria is a large and speciose clade of anomodont therapsid that includes the highly diverse dicynodonts and a small number of closely related basal genera (to the exclusion of Venyukovioidea and more basal anomodonts)—although the total composition and taxonomic scope of Chainosauria is in flux. Chainosauria was named in 1923 to group together the dicynodonts and their close relatives, namely three small anomodont genera from South Africa (Galechirus, Galeops, and Galepus) that made up the now defunct group 'Dromasauria'. The name soon fell into disuse, however, as it was functionally r

Dicynodontoidea is an infraorder of dicynodont therapsids that includes the famous dicynodont Dicynodon, Lystrosaurus and the Triassic Kannemeyeriiformes, as well as numerous other closely related species. The name was coined by American paleontologist Everett C. Olson in 1941 as an infraorder, despite using the typical "-oidea" suffix of superfamilies, and was later redefined under a phylogenetic context in 2009 by paleontologist Christian F. Kammerer.

Venyukovioidea is an infraorder of anomodont therapsids related to dicynodonts from the Permian of Russia. They have also been known as Venjukovioidea, as well as by the similar names Venyukoviamorpha or Venjukoviamorpha in literature. This in part owes to a misspelling by Russian palaeontologist Ivan Efremov in 1940 when he mistakenly spelt Venyukovia, the namesake of the group, with a 'j' instead of a 'y' (i.e. Venjukovia), which permeated through subsequent therapsid literature before the mistake was caught and corrected. The order Ulemicia has also been coined for a similar taxonomic conce

Pylaecephalidae is a family of dicynodont therapsids that includes Diictodon, Robertia, and Prosictodon from the Permian of South Africa. Pylaecephalids were small burrowing dicynodonts with long tusks. The family was first named in 1934 and was redefined in 2009. Diictodontidae and Robertiidae are considered junior synonyms of Pylaecephalidae; although Pylaecephalus itself is considered a junior synonym of Diictodon, the name Pylaecephalidae predates these names and therefore takes priority.

Akidnognathidae is an extinct family of therocephalian therapsids from the Late Permian and Early Triassic of South Africa, Russia and China. The family includes many large-bodied therocephalians that were probably carnivorous, including Moschorhinus and Olivierosuchus. One akidnognathid, Euchambersia, may even have been venomous. Akidnognathids have robust skulls with a pair of large caniniform teeth in their upper jaws. The family is morphologically intermediate between the more basal therocephalian group Scylacosauridae and the more derived group Baurioidea.

Trochosaurus (from , 'badger' and , 'lizard') is a dubious genus of therocephalian therapsid from South Africa, to which various species were once assigned. The genus was based upon multiple weathered and distorted fossils of therocephalians of the family Lycosuchidae. Like other lycosuchids, specimens placed in Trochosaurus have only five large incisors in each premaxilla, seemingly two functional "double canines" in each maxilla (of which the second was supposedly slightly larger in Trochosaurus), and few postcanines. However, the fossils lack any further diagnostic traits to justify referri

Moschowhaitsia is an extinct genus of therocephalian therapsids from the Late Permian (Guadalupian) of Russia and China. The type species, Moschowhaitsia vjuschkovi, was discovered in the Changxingian-aged Archosaurus Assemblage Zone of Russia and named in 1963 by Russian palaeontologist Leonid Petrovich Tatarinov. A second species was discovered in Jingtai County of Gansu, China in 2020 and named as M. lidaqingi in 2023 by Jun Liu and Fernando Abdala, the first whaitsiid therocephalian to be discovered in China. It was among the larger carnivores in the faunal assemblages it occurred in, with

Nothogomphodon is a genus of therocephalian therapsids. It is classified within the family Bauriidae and placed within its own subfamily, Nothogomphodontinae.

Anomocephaloidea is a clade of basal anomodont therapsids related to the dicynodonts known from what is now South Africa and Brazil during the Middle Permian. It includes only two species, Anomocephalus africanus (the clade's namesake) from the Karoo Basin of South Africa and Tiarajudens eccentricus from the Paraná Basin of Brazil. Anomocephaloidea was named in 2011 with the discovery of Tiarajudens, although Anomocephalus itself has been known since 1999.

Malasaurus is an extinct genus of therocephalian therapsids which lived in south-eastern Finland and north-western Russia. The type species is Malasaurus germanus.