Probainognathidae is an extinct family of meat-eating mammal-like reptiles (Therapsids) which lived during the Upper Triassic. According to some authors, it has perhaps two known members: Probainognathus from South America, and the somewhat later Lepagia from Europe. The family was established by Romer in 1973. Its members were closely related to the even more exotically named Chiniquodontidae.
Both genera were small animals. Probainognathus, known from a number of specimens, was about 10 cm in length and extremely mammal-like in terms of its anatomy. Remains of Lepagia are restricted to teeth. These most closely resemble the dentition of other carnivorous cynodonts of the Upper Triassic.
