Pristerognathus is an extinct genus of therocephalian, known from the late Middle Permian (Capitanian) of South Africa. It lends its name to the Pristerognathus Assemblage Zone of the Beaufort Group of South African geological strata. Pristerognathus was a medium-sized therocephalian with a 25 cm (9.8 in) skull and a total length up to 1.5 m (4 ft 11 in). These animals were roughly dog-sized, and are characterized by long, narrow skulls with large canines. They are likely to have lived in woodlands, and preyed on smaller therapsids and millerettids of the time.