Therapsida is a clade comprising a major group of eupelycosaurian synapsids that includes mammals and their ancestors and close relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more underneath the body, resulting in a more "standing" quadrupedal posture, as opposed to the lower sprawling posture of many reptiles and amphibians.
Deuterosaurus is an extinct genus of dinocephalian therapsids, one of the non-mammalian synapsids dominating the land during the late Paleozoic.
Biarmosuchia is an extinct clade of non-mammalian synapsids from the Permian. Biarmosuchians are the most basal group of the therapsids. They were moderately-sized, lightly built carnivores, intermediate in form between basal sphenacodont "pelycosaurs" and more advanced therapsids. Biarmosuchians were rare components of Permian ecosystems, and the majority of species belong to the clade Burnetiamorpha, which are characterized by elaborate cranial ornamentation.
Sphenacodontoidea is a node-based clade that is defined to include the most recent common ancestor of Sphenacodontidae and Therapsida and its descendants. Sphenacodontoids are characterised by a number of synapomorphies concerning proportions of the bones of the skull and the teeth.
Tetraceratops insignis is an extinct synapsid from the Early Permian that was formerly considered the earliest known representative of Therapsida, a group that includes mammals and their close extinct relatives. It is known from a single 90-millimetre-long (3.5 in) skull, discovered in Texas in 1908. According to a 2020 study, it should be classified as a primitive non-therapsid sphenacodont rather than a genuine basal therapsid.
Phthinosuchus is an extinct genus of therapsids from the Middle Permian of Russia. Phthinosuchus is the sole member of the family Phthinosuchidae. Phthinosuchus may have been one of the most primitive therapsids, meaning that its ancestors may have branched off early from the main therapsid line.
Galechirus is an extinct genus of anomodont therapsids. It was about 30 cm (1 ft) long.
Pristerognathus is an extinct genus of therocephalian, known from the late Middle Permian (Capitanian) of South Africa. It lends its name to the Pristerognathus Assemblage Zone of the Beaufort Group of South African geological strata. Pristerognathus was a medium-sized therocephalian with a 25 cm (9.8 in) skull and a total length up to 1.5 m.
Brithopus is an extinct genus of dinocephalian therapsids. It contains a single species, Brithopus priscus, known from fragmentary remains found in the Copper Sandstones near Isheevo, Russia.
Archaeosyodon is an extinct genus of dinocephalian therapsids. It was medium-sized, reaching about 1.5–2 m (4–5 ft) in length.
Nikkasaurus is an extinct genus of therapsids first named and described by Ivakhnenko.
Ivantosaurus is an extinct genus of therapsid that lived in Russia during the Wordian stage of the Permian period, named in honor of paleontologist Ivan Antonovich Efremov.
Cistecephaloides is an extinct genus of dicynodont therapsids of the Cistecephalus Assemblage Zone, Beaufort Group of South Africa.
Niaftasuchus is an extinct genus of therapsids. Its type and only named species is Niaftasuchus zekkeli.
Oudenodon is an extinct genus of dicynodont. It was common throughout southern Africa during the Late Permian. Several species of Oudenodon are known. Both O. bainii, the type species, and O. grandis are known from South Africa. Specimens of O. luangwensis have been found from Zambia. One species, O. sakamenensis, is the only Permian therapsid yet described from Madagascar. It is the type genus of the family Oudenodontidae, which includes members such as Tropidostoma.
Reiszia is an extinct genus of therapsids from European Russia belonging to the family Nikkasauridae.
Zorillodontops is an extinct genus of therocephalian therapsids from the Early Triassic of South Africa.
Ulemica is an extinct genus of venyukovioid therapsids, a type of anomodont related to dicynodonts. It lived during the Middle Permian period in what is now Russia, and is known from the Isheevo assemblage of the Amanakskaya Formation. The type species, U. invisa, was originally placed in the genus Venyukovia by Russian palaeontologist Ivan Efremov in 1940. It was later given its own genus Ulemica in 1996 by Mikhaïl Ivakhnenko, who also named a second species U. efremovi. Efremov had originally intended to name the fossils of U. invisa as 'Myctosuchus invisus', however, he later recognised their similarity to Venyukovia and chose to assign the Isheevo material to this genus and leaving 'Myctosuchus' a nomen nudum.
Raranimus is an extinct genus of therapsids of the Middle Permian. It was described in 2009 from a partial skull found in 1998 from the Dashankou locality of the Qingtoushan Formation, outcropping in the Qilian Mountains of Gansu, China. The genus is the most basal known member of the clade Therapsida, to which the later Mammalia belong.
Tiarajudens is an extinct genus of saber-toothed herbivorous anomodonts which lived during the Middle Permian period in what is now Rio Grande do Sul, Brazil. It is known from the holotype UFRGS PV393P, a nearly complete skull. The type species T. eccentricus was named in 2011.
