Dicynodontia is a taxon of anomodont therapsids with beginnings in the mid-Permian, which were dominant in the Late Permian, survived the Permian Extinction that wiped out most other therapsids and continued on throughout the Triassic before dying out at the end of the period. Dicynodonts were herbivorous animals with two tusks, hence their name, which means 'two dog tooth'. They are also the most successful and diverse of the non-mammalian therapsids, with over 70 genera known, varying from rat- to elephant-sized.
Robertia is an extinct genus of small herbivorous dicynodonts from the Middle to Late Permian of South Africa, between 260 and 265 million years ago. It is a monospecific genus, consisting of the type-species R. broomiana, which was classified by Lieuwe Dirk Boonstra in 1948 and named in honor of Robert Broom for his study of South African mammal-like reptiles.
Dicynodon is a genus of dicynodont therapsid that flourished during the Upper Permian period. Like all dicynodonts, it was herbivorous. This animal was toothless, except for prominent tusks, hence the name. It probably cropped vegetation with a horny beak, much like a tortoise, while the tusks may have been used for digging up roots and tubers.
Dicynodontoides is a genus of small to medium-bodied, herbivorous, emydopoid dicynodonts from the Late Permian. The name Dicynodontoides references its “dicynodont-like” appearance due to the caniniform tusks featured by most members of this infraorder. Kingoria, a junior synonym, has been used more widely in the literature than the more obscure Dicynodontoides, which is similar-sounding to another distantly related genus of dicynodont, Dicynodon. Two species are recognized: D. recurvidens from South Africa, and D. nowacki from Tanzania.
Eosimops is an extinct genus of pylaecephalid dicynodonts. They were small synapsids superficially resembling modern mammals. Eosimops is known from several skull specimens, as well as one complete skeleton. Eosimops lived during the Middle Permian of South Africa.
Geikia is an extinct genus of dicynodont therapsids from the late Permian. The abundance and diversity of dicynodonts during this period, combined with incomplete or inadequately prepared specimens, have led to challenges in determining relationships within this taxon. Only two species, Geikia locusticeps and Geikia elginensis have been assigned to this genus. While this is the currently accepted classification, fossil record limitations have led to repeated debate on the genus assignments of these species.
Odontocyclops : Greek: ondont-“tooth” Greek: kyklops- “round eye”, a kind of Greek mythological giant with one eye in the midline” =toothy cyclops. The 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 Arfrica 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.
Pelanomodon is an extinct genus of dicynodont therapsids that lived in the Late Permian period. Fossil evidence of this genus is principally found in the Karoo Basin of South Africa, in the Dicynodon Assemblage Zone. Lack of fossil record after the Late Permian epoch suggests that Pelanomodon fell victim to the Permian-Triassic extinction event.
Aulacephalodon is an extinct genus of medium-sized dicynodonts, or non-mammalian synapsids, that lived during Permian period, about 299-252 million years ago. Individuals of Aulacephalodon are commonly found in the Lower Beaufort Group of the Karoo Supergroup of South Africa and Zambia. Rising to dominance during the Late Permian, Aulacephalodon were the dominant terrestrial vertebrate herbivores until they became extinct during the Triassic. No living relatives of Aulacephalodon exist today. Two species have been named, the type species, A. bainii, and a second species, A. peavoti. However, debate exists among paleontologists if A. peavoti is a true member of the genus Aulacephalodon. Therefore, a majority of the information known about Aulacephalodon is in reference to discoveries about A. bainii.
Vivaxosaurus is a genus of dicynodont from Late Permian (Changhsingian) of Russia. It has been found at Sokolki on the Northern Dvina River near Kotlas in Arkhangelsk Oblast, Russia. It lived during the latest Permian, and was a contemporary of Inostrancevia, Scutosaurus and Dvinia. Like all members of the genus, this animal was toothless, except for prominent tusks, and probably cropped vegetation with a horny beak, like a tortoise.
Elph is an extinct genus of dicynodont therapsids from Russia. Four specimens have been found from the Sokolki Assemblage in European Russia, representing a fauna that dates back to the Late Permian. Elph was a small herbivore that lived alongside carnivorous akidnognathids and inostranceviids, as well as larger herbivores like Dicynodon and pareiasaurids. The type species E. borealis was named in 1999. Elph has a short snout and tusks and is closely related to Interpresosaurus and Katumbia.
Sintocephalus is an extinct genus of dicynodont therapsid from the Late Permian of South Africa. Fossils are known from the Cistecephalus Assemblage Zone of the Beaufort Group. The type species of Sintocephalus, S. alticeps, was first named in 1913 as a species of Dicynodon. The genus was erected in 1934, but in subsequent years its species were often regarded as members of other dicynodont genera.
Gordonia is an extinct genus of dicynodont therapsid from the Late Permian of Scotland. Fossils have been found from the Elgin sandstone of Cutties Hillock Quarry in Elgin, Moray. These are among the many reptile fossils referred to as the Elgin Reptiles. Gordonia was named in 1893 with four species: G. traquairi, G. duffiana, G. huxleyana, and G. juddiana. Currently, the only recognized species is the type G. traquairi. All other species are considered synonyms of the type.
Turfanodon is an extinct genus of dicynodont therapsid from the Late Permian Sunan, Guodikeng, and Naobaogou Formations of China. The holotype of T. bogdaensis was discovered between 1963-1964 and was originally named in 1973 by A. Sun with the type species Turfanodon bogdaensis, Turfanodon was reclassified as a junior synonym of the related Dicynodon in 1988 by G. M. King. T. bogdaensis remained a species of Dicynodon for over two decades before the genus was reinstated in 2011 in a revision of the taxonomy of Dicynodon by palaeontologist Christian Kammerer. A second species from Inner Mongolia, T. jiufengensis, was named in 2021 by palaeontologist Jun Liu from a nearly complete skeleton and other referred bones. Turfanodon was a relatively large dicynodont, and similar in appearance to the related Daptocephalus from South Africa.
Bulbasaurus is an extinct genus of dicynodont that is known from the Lopingian epoch of the Late Permian period of what is now South Africa, containing the type and only species B. phylloxyron. It was formerly considered as belonging to Tropidostoma; however, due to numerous differences from Tropidostoma in terms of skull morphology and size, it has been reclassified the earliest known member of the family Geikiidae, and the only member of the group known from the Tropidostoma Assemblage Zone. Within the Geikiidae, it has been placed close to Aulacocephalodon, although a more basal position is not implausible.
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.
Repelinosaurus is an extinct genus of dicynodont from the Purple Claystone Formation 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 R. robustus. Repelinosaurus was originally described as the earliest known kannemeyeriiform dicynodont, supporting the idea of a more rapid radiation of the Triassic kannemeyeriiform dicynodonts during the Early Triassic following the Permian mass extinction. However, it may alternatively be more closely related to the Permian Dicynodon. The discovery of a potential early kannemeyeriiform in an understudied locality like Laos highlights the importance of such places in dicynodont research, which has been largely focused on historically important localities such as the Karoo Basin of South Africa.
Ufudocyclops is an extinct genus of stahleckeriid dicynodont from the Middle Triassic of South Africa. It was found in the Burgersdorp Formation, part of the uppermost Cynognathus Assemblage Zone of the Beaufort Group in the Karoo Basin. The type and only known species is U. mukanelai. It was a large, beaked herbivore like other Triassic dicynodonts, lacking tusks, and is mostly characterised by unique features of the skull. It is known from three specimens, two of which were previously referred to the Tanzanian dicynodont Angonisaurus. The separation of Ufudocyclops from Angonisaurus indicates that the Middle Triassic fauna of the Beaufort Group in South Africa was part of a larger shared fauna with those of the Manda Beds in Tanzania, as was previously supposed, and suggests that they were separated as more localised faunas, possibly by geographic barriers or in time. Ufudocyclops then would have been a unique part of the uppermost Cynognathus Assemblage Zone in South Africa. It is also the oldest known member of the family Stahleckeriidae, and implies that the family was already diversifying in the Middle Triassic alongside other kannemeyeriiforms, not just in the Late Triassic after other families died out.
Kembawacela is an extinct genus of cistecephalid dicynodont from the Late Permian Madumabisa Mudstone Formation of Zambia. It contains the type and only species, Kembawacela kitchingi. 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.
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.
