Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and 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, as opposed to the sprawling posture of many reptiles and salamanders.
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.
Therocephalia is an extinct order of eutheriodont therapsids from the Permian and Triassic. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their teeth, suggest that they were carnivores. Like other non-mammalian synapsids, therocephalians were once described as "mammal-like reptiles". Therocephalia is the group most closely related to the cynodonts, which gave rise to the mammals. This relationship takes evidence in a variety of skeletal features.
The Tapinocephalus Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the middle Abrahamskraal Formation, Adelaide Subgroup of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. The thickest outcrops, reaching approximately 2,000 metres (6,600 ft), occur from Merweville and Leeu-Gamka in its southernmost exposures, from Sutherland through to Beaufort West where outcrops start to only be found in the south-east, north of Oudshoorn and Willowmore, reaching up to areas south of Graaff-Reinet. Its northernmost exposures occur around the towns Fraserburg and Victoria West. The Tapinocephalus Assemblage Zone is the second biozone of the Beaufort Group.
Euchambersia is an extinct genus of therocephalian therapsids that lived during the Late Permian in what is now South Africa and China. The genus contains two species. The type species E. mirabilis was named by paleontologist Robert Broom in 1931 from a skull missing the lower jaw. A second skull, belonging to a probably immature individual, was later described. In 2022, a second species, E. liuyudongi, was named by Jun Liu and Fernando Abdala from a well-preserved skull. It is a member of the family Akidnognathidae, which historically has also been referred by as the synonymous Euchambersiidae.
Rubidgea is a genus of gorgonopsid from the upper Permian of South Africa and Tanzania, containing the species Rubidgea atrox. The generic name Rubidgea is sometimes believed to be derived from the surname of renowned Karoo paleontologist, Professor Bruce Rubidge, who has contributed to much of the research conducted on therapsids of the Karoo Basin. However, this generic name was actually erected in honor of Rubidge's paternal grandfather, Sydney Rubidge, who was a renowned fossil hunter. Its species name atrox is derived from Latin, meaning “fierce, savage, terrible”. Rubidgea is part of the gorgonopsian subfamily Rubidgeinae, a derived group of large-bodied gorgonopsians restricted to the Late Permian (Lopingian). The subfamily Rubidgeinae first appeared in the Tropidostoma Assemblage Zone. They reached their highest diversity in the Cistecephalus and Daptocephalus assemblage zones of the Beaufort Group in South Africa.
Theriognathus is an extinct genus of therocephalian therapsid belonging to the family Whaitsiidae, known from fossils from South Africa, Zambia, and Tanzania. Theriognathus has been dated as existing during the Late Permian. Although Theriognathus means mammal jaw, the lower jaw is actually made up of several bones as seen in modern reptiles, in contrast to mammals. Theriognathus displayed many different reptilian and mammalian characteristics. For example, Theriognathus had canine teeth like mammals, and a secondary palate, multiple bones in the mandible, and a typical reptilian jaw joint, all characteristics of reptiles. It is speculated that Theriognathus was either carnivorous or omnivorous based on its teeth, and was suited to hunting small prey in undergrowth. This synapsid adopted a sleek profile of a mammalian predator, with a narrow snout and around 1 meter long. Theriognathus is represented by 56 specimens in the fossil record.
Scylacops is an extinct genus of Gorgonopsia. It was first named by Broom in 1913, and contains two species, S. bigendens, and S. capensis. Its fossils have been found in South Africa and Zambia. It is believed to be closely related to the Gorgonopsian Sauroctonus progressus. Scylacops was a moderately sized Gorgonopsid.
Paraburnetia is an extinct genus of biarmosuchian therapsids from the Late Permian of South Africa. It is known for its species P. sneeubergensis and belongs to the family Burnetiidae. Paraburnetia lived just before the Permian–Triassic mass extinction event.
Lobalopex is an extinct genus of biarmosuchian therapsids. It was alive during the Late Permian and has only been found in the Teekloof Formation in South Africa. The only known species of the genus is Lobalopex mordax. Lobalopex is part of the clade of Burnetiamorpha, which have fossil specimens located in multiple areas of Africa and Russia.
Megawhaitsia is an extinct genus of large therocephalian therapsids who lived during the Late Permian (Wuchiapingian) in what is now Eastern Europe. The only known species is M. patrichae, described in 2008 from several fossils discovered in various oblasts of European Russia. The fossils are representative of a large animal whose skull size is estimated to be 40–50 cm (16–20 in) long.
Compsodon is an extinct genus of dicynodont belonging to the superfamily Emydopoidea. Fossils have been found in the Balfour Formation of South Africa and the Madumabisa Mudstone of Zambia.
Chthonosaurus is an extinct genus of eutherocephalian therapsids from the Late Permian Kutulukskaya Formation of Russia. The type species Chthonosaurus velocidens was named in 1955.
Odontocyclops is an extinct genus of Dicynodonts that lived in the Late Permian. Dicynodonts are believed to be the first major assemblage of terrestrial herbivores. Fossils of Odontocyclops have been found in the Karoo Basin of South Africa and the Luangwa Valley of Zambia. The phylogenetic classification of Odontocyclops has been long under debate, but most current research places them as their own genus of Dicynodonts and being very closely related to Rhachiocephalus and Oudenodon.
Katumbia is a genus of dicynodont from Late Permian (Changhsingian) Kawinga Formation of the Ruhuhu Basin, Tanzania. and possibly the Upper Madumabisa Mudstone Formation of the Luangwa Basin, Zambia. The type species, K. parringtoni, was originally referred to the genus Cryptocynodon, which is now recognized as a junior synonym of Endothiodon.
Christian Alfred Sidor is an American vertebrate paleontologist. He is currently a Professor in the Department of Biology, University of Washington in Seattle, as well as Curator of Vertebrate Paleontology and Associate Director for Research and Collections at the Burke Museum of Natural History and Culture. His research focuses on Permian and Triassic tetrapod evolution, especially on therapsids.
Bauriidae is an extinct family of therocephalian therapsids. Bauriids were the latest-surviving group of therocephalians after the Permian–Triassic extinction event, going extinct in the Middle Triassic. They are among the most advanced eutherocephalians and possess several mammal-like features such as a secondary palate and wide postcanine teeth at the back of the jaws. Unlike other therocephalians, bauriids were herbivorous. They were also smaller than earlier members of the group. Two subfamilies are classified within Bauriidae: Nothogomphodontinae and Bauriinae.
The Abrahamskraal Formation is a geological formation and is found in numerous localities in the Northern Cape, Western Cape, and the Eastern Cape of South Africa. It is the lowermost formation of the Adelaide Subgroup of the Beaufort Group, a major geological group that forms part of the greater Karoo Supergroup. It represents the first fully terrestrial geological deposits of the Karoo Basin. Outcrops of the Abrahamskraal Formation are found from the small town Middelpos in its westernmost localities, then around Sutherland, the Moordenaarskaroo north of Laingsburg, Williston, Fraserburg, Leeu-Gamka, Loxton, and Victoria West in the Western Cape and Northern Cape. In the Eastern Cape outcrops are known from Rietbron, north of Klipplaat and Grahamstown, and also southwest of East London.
Syops is an extinct genus of dicynodont therapsid. The type species S. vanhoepeni was first named in 1938 as Dicynodon vanhoepeni. Fossils of the genus have been found in the Cistecephalus Assemblage Zone in the Usili Formation of the Ruhuhu Basin, Tanzania and the Upper Madumabisa Mudstone Formation of the Luangwa Basin, Zambia. Its phylogenetic placement is somewhat uncertain, with multiple different studies finding it as either a basal geikiid, rhachiocephalid a dicynodontoid more derived than the most basal genera but less derived than Lystrosauridae, or a lystrosaurid.
Kembawacela is an extinct genus of cistecephalid dicynodont from the Late Permian of East Africa. The genus contains two known species, the type species Kembawacela kitchingi from the Madumabisa Mudstone Formation of Zambia described in 2019, and a second species, K. yajuwayeyi, from the Chiweta Beds of Malawi described in 2022. Like other cistecephalids, Kembawacela was specialised for a fossorial, burrowing lifestyle similar to modern day moles. It is unique amongst cistecephalids for the presence of a pair of tusks in the upper jaw, characteristic of many other dicynodonts but lost in other cistecephalids. It is likely that Kembawacela was a locally endemic species of cistecephalid in the Luangwa Basin of Zambia.
