Cynodonts are eutheriodont therapsids that first appeared in the Late Permian, and extensively diversified after the Permian–Triassic extinction event. Mammals are cynodonts, as are their extinct ancestors and close relatives (Mammaliaformes), having evolved from advanced probainognathian cynodonts during the Late Triassic.
Chiniquodon is an extinct genus of carnivorous cynodonts, which lived during the Late Triassic (Carnian) in South America and Africa. Chiniquodon was closely related to the genus Aleodon, and close to the ancestry of mammals.
Azendohsaurus is an extinct genus of herbivorous archosauromorph reptile from roughly the late Middle to early Late Triassic Period of Morocco and Madagascar. The type species, Azendohsaurus laaroussii, was described and named by Jean-Michel Dutuit in 1972 based on partial jaw fragments and some teeth from Morocco. A second species from Madagascar, A. madagaskarensis, was first described in 2010 by John J. Flynn and colleagues from a multitude of specimens representing almost the entire skeleton. The generic name "Azendoh lizard" is for the village of Azendoh, a local village near where it was first discovered in the Atlas Mountains. It was a bulky quadruped that unlike other early archosauromorphs had a relatively short tail and robust limbs that were held in an odd mix of sprawled hind limbs and raised forelimbs. It had a long neck and a proportionately small head with remarkably sauropod-like jaws and teeth.
Massetognathus is an extinct genus of plant-eating traversodontid cynodonts. They lived during the Triassic Period about 235 million years ago, and are known from the Chañares Formation in Argentina and the Santa Maria Formation in Brazil.
Tritylodontidae is an extinct family of small to medium-sized, highly specialized mammal-like cynodonts, with several mammalian traits including erect limbs, endothermy and details of the skeleton. They were the last-known family of the non-mammaliaform synapsids, persisting into the Early Cretaceous.
Traversodontidae is an extinct family of herbivorous cynodonts. Traversodonts were primarily Gondwanan, with many species known from Africa and South America. Recently, traversodonts have also been found from Europe and North America. Traversodonts first appeared in the Middle Triassic and diversified in the Late Triassic before going extinct at the end of the epoch. The family Traversodontidae was erected by Friedrich von Huene in 1936 for cynodonts first found in São Pedro do Sul in Paleorrota, Brazil.
Exaeretodon is an extinct genus of fairly large, low-slung traversodontid cynodonts from the southern parts of Pangea. Four species are known, from various formations. E. argentinus is from the Carnian-age Cancha de Bochas Member of the Ischigualasto Formation in the Ischigualasto-Villa Unión Basin in northwestern Argentina. E. major and E. riograndensis are from the Carnian-age portion of the Santa Maria Formation of the Paraná Basin in southeastern Brazil. E. statisticae is from the Carnian-age Lower Maleri Formation of India.
The Tecovas Formation is a geological formation in the Texas panhandle and eastern New Mexico. It is one of several formations encompassed by the Late Triassic Dockum Group.
Protuberum is an extinct genus of traversodontid cynodonts known from a single species Protuberum cabralense, from the Middle Triassic of Brazil.
Dadadon is an extinct genus of traversodontid cynodonts which existed in Madagascar during the late Middle Triassic. The only species in the genus is Dadadon isaloi.
Pascualgnathus is an extinct genus of traversodontid cynodonts from the Middle Triassic of Argentina. Fossils have been found from the Río Seco de la Quebrada Formation of the Puesto Viejo Group. The type species P. polanskii was named in 1966.
Boreogomphodon is an extinct genus of traversodontid cynodonts from the Late Triassic of the eastern United States. Fossils have been found from the Turkey Branch Formation in Virginia and the Pekin Formation of North Carolina.
Gomphodontosuchinae is a subfamily of Triassic traversodontid cynodonts. It includes the genera Gomphodontosuchus, Exaeretodon, Santagnathus, Siriusgnathus, Menadon, Proexaeretodon,Protuberum, Ruberodon and Scalenodontoides.
Massetognathinae is an extinct subfamily of cynodonts in the family Traversodontidae. It includes four species from the Middle and Late Triassic: Massetognathus pascuali from Argentina, Massetognathus ochagaviae and Santacruzodon hopsoni from southern Brazil, and Dadadon isaloi from Madagascar. Massetognathines have several distinguishing characteristics, including flattened skulls, small canine teeth, and postcanine teeth with three cusps on their outer edges. Massetgognathinae was defined by Kammerer et al. (2012) as the clade containing all traversodontids more closely related to Massetognathus pascuali than to Gomphodontosuchus brasiliensis, and is the sister taxon of the traversodontid subfamily Gomphodontosuchinae, which was defined by Kammerer et al. (2008) as all traverodontids more closely related to G. brasiliensis than to M. pascuali.
Titanogomphodon is an extinct genus of diademodontid cynodonts from the Middle Triassic Omingonde Formation of Namibia. It is known from a single partial skull that was described in 1973 from the Omingonde Formation. The type and only species is Titanogomphodon crassus. At about 40 centimetres (16 in), the skull of Titanogomphodon was significantly larger than that of its closest relative, Diademodon. Its teeth are similar to those of another group of cynodonts called Traversodontidae, but the similarities are likely the result of convergent evolution. Aside from its larger size, Titanogomphodon differs from Diademodon in having a bony projection on the postorbital bar behind the eye socket.
The Río Seco de la Quebrada Formation is a Triassic geological formation in Mendoza Province, Argentina. Fossils of cynodonts such as Cynognathus, Diademodon, and Pascualgnathus have been found in this formation, along with dicynodonts such as Vinceria and Acratophorus. Based on biostratigraphy, the Río Seco de la Quebrada Formation is considered to have formed during the Anisian stage, as it shares fauna with the upper subzones of the Cynognathus Assemblage Zone in South Africa. However, radiometric dating controversially argues that it was deposited during the early Carnian stage, 10 million years younger than expected otherwise.
Isalo II, also known as the Makay Formation, is an informal Triassic geological unit in Madagascar.
Scalenodontoides is an extinct genus of Traversodontidae, a family of herbivorous cynodonts. It lived during the Late Triassic in what is now South Africa. Its type species is Scalenodontoides macrodontes. It was named in 1957 by A. W. Crompton and F. Ellenberger. Arctotraversodon plemmyrodon was originally classified as a species of Scalenodontoides, but was given its own genus in 1992. It is found in the Scalenodontoides Assemblage Zone of the Elliot Formation, which is named for it. It is one of the geologically youngest traversodontids, alongside the putative traversodontid Boreogomphodon. It is closely related to Exaeretodon and Siriusgnathus, but is distinguished by the presence of a shelf-like expansion of its parietal called the nuchal table. Though the largest known complete skull is only 248 millimetres (9.8 in) long, it may have been the largest non-mammalian cynodont, as an incomplete snout would have belonged to a specimen with an estimated skull length of 617 millimetres (24.3 in).
Mambachiton is an extinct genus of basal avemetatarsalian from the Middle/Upper Triassic Makay Formation of Madagascar. The genus contains a single species, M. fiandohana, known from a partial skeleton with articulated osteoderms.
