Tritylodontidae

The tritylodont dentition differed from that of most other cynodonts: They did not have canine teeth, and the front pair of incisors were enlarged and were very similar to those of modern-day rodents.

A recent Kayentatherium shows that they indeed produced undeveloped young, but at litter sizes much larger than any monotreme or marsupial, at around 38 perinates.

[12] In 2023 skulls and teeth from dozens of tritylodonts were discovered at Lake Powell on the Colorado River in the United States, with more discoveries expected which may help to understand the history and evolution of mammals.

Watson and other paleontologists noted that tritylodontids lacked the dentary and squamosal jaw articulation that was characteristic of early mammals.

Under this classification, which was widely accepted in the following decades, Tritylodontidae was previous considered to be part of Gomphodontia, a larger group within Cynognathia.

Beginning with Kemp (1983) harvp error: no target: CITEREFKemp1983 (help), Tritylodontidae has been proposed by numerous studies as a member of Probainognathia, the cynodont group containing mammals and related taxa.

[17] Ruta et al. (2013)'s phylogenetic analysis which is partially based on Liu & Olsen (2010) places Tritylodontidae in a more derived position than Brasilodontidae.

[5] Lumkuia Ecteninion Aleodon Chiniquodon Probainognathus Trucidocynodon Therioherpeton Riograndia Chaliminia Elliotherium Diarthrognathus Pachygenelus Brasilitherium Brasilodon Oligokyphus Kayentatherium Tritylodon Bienotherium Sinoconodon Morganucodon