Lucianosaurus is an extinct genus of amniote of unknown affinities, known only from teeth. Initially described as a basal ornithischian dinosaur, subsequently reclassified as a member of the clade Archosauriformes of uncertain phylogenetic placement and later, taking into account the similarity of its teeth to the teeth of traversodontid cynodonts such as Dadadon, as an amniote of uncertain affinities.
Cynognathia is one of two major clades of cynodonts, the other being Probainognathia. Cynognathians included the large carnivorous genus Cynognathus and the herbivorous or omnivorous gomphodonts such as traversodontids. Cynognathians can be identified by several synapomorphies including a very deep zygomatic arch that extends above the middle of the orbit.
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.
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.
Luangwa is an extinct genus of traversodontid cynodonts. The species Luangwa drysdalli was discovered 1963 in the valley of the Luangwa river in Zambia, Africa. Luangwa lived in the Triassic period 240 Million years ago.
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.
Andescynodon is a genus of traversodontid cynodonts from the Middle Triassic of Argentina. Fossils are known from the Cerro de las Cabras and Cacheutá Formations. Andescynodon is one of the most basal traversodontids. Another traversodontid called Rusconiodon has also been identified from the Cerro de las Cabras Formation but is now considered a junior synonym of Andescynodon.
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.
Arctotraversodon is an extinct genus of traversodontid cynodonts from the Late Triassic of Canada. Fossils first described from the Wolfville Formation in Nova Scotia in 1984 represented the first known traversodontid from North America. The type and only species is A. plemmyridon and is represented by teeth and several dentary bones.
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.
Maubeugia is an extinct genus of traversodontid cynodonts from the Late Triassic of France. Isolated postcanine teeth are known from Saint-Nicolas-de-Port in northeastern France. The type species M. lotharingica was named in 1997. Many other cynodont teeth were found alongside those of Maubeugia, including those of dromatheriids, probainognathids, and other traversodontids. The size of its teeth indicates that Maubeugia was a dwarf traversodontid. The deposit in which the teeth were found indicates that it lived along the shoreline of an ocean.
Habayia is an extinct genus of traversodontid cynodonts from the Late Triassic of Belgium. A single postcanine tooth was found in Habay-la-Vieille in southern Belgium. Based on the size of the tooth, Habayia was very small. Habayia lived during the Rhaetian stage of the Late Triassic at a time when western Europe was an island archipelago due to high sea levels. The small size of Habayia may be a result of insular dwarfism.
Colbertosaurus is an extinct genus of traversodontid cynodonts from the Middle Triassic of Argentina. A single species C. muralis was named in 1954 from a fragmentary jaw. Colbertosaurus was originally placed in Ictidosauria, an outdated name for a group of cynodonts that includes tritheledontids. It is the only cynodont known from the Potrerillos Formation and is similar in appearance to Pascualgnathus from the Puesto Viejo Formation. The similarity between the two traversodontids has been used to correlate the two formations.
Scalenodon is an extinct genus of traversodontid cynodonts from the Middle Triassic of Africa and possibly Russia. The type species S. angustifrons was named in 1946 and several other species were named in the following years. Most of the species from Africa are now thought to belong to different genera than Scalenodon.
Gomphodontosuchinae is a subfamily of Triassic traversodontid cynodonts. It includes the genera Gomphodontosuchus, Exaeretodon, Santagnathus, Siriusgnathus, Menadon, Proexaeretodon,Protuberum, Ruberodon and Scalenodontoides.
Mandagomphodon is an extinct genus of traversodontid cynodonts from the Middle Triassic Lifua Member of the Manda Beds of Ruhuhu Valley, Tanzania. The type species Mandagomphodon hirschsoni was named by Crompton in 1972 as a species referable to Scalenodon. Later studies, including a 2003 phylogenetic analysis of traversodontid relationships, did not find the species of Scalenodon from the Manda Formation to form a single clade, meaning that many were not referable to the genus. The study suggested that S. hirschsoni had more in common with other traversodontids like Luangwa. S. attridgei was viewed as a possible synonym of S. charigi, which was also found to be only distantly related to S. angustifrons. Therefore, a new generic name Mandagomphodon was erected for S. hirschsoni by James A. Hopson in 2013.
Ruberodon is an extinct genus of traversodontid cynodonts known from the type and only species Ruberodon roychowdhurii from the Late Triassic of India. Ruberodon was named in 2015 on the basis of several isolated lower jaws found in the Tiki Formation. The lower jaw of Ruberodon has three pairs of incisors, one pair of canines, and 9 pairs of postcanine teeth. The first pair of incisors is enlarged and protrudes forward from the tip of the jaw and there is a gap called a diastema between the canines and postcanines. Phylogenetic analysis indicates that among traversodontids, R. roychowdhurii is most closely related to Exaeretodon statisticae, which is also from India.
Etjoia is an extinct genus of traversodontid cynodonts that lived during the Middle Triassic or Late Triassic period in southern Africa. This medium-sized omnivorous cynognathian provides important information on the dental evolution of early diverging gomphodonts and traversodontids.
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).
