Trochosuchidae
Trochosuchidae is an extinct family of therocephalian therapsids from the Permian period. It includes the genera "Trochosaurus", "Trochosuchus", "Trochorhinus", and "Hyaenasuchus". Trochosuchids are known only from the "Tapinocephalus" Assemblage Zone of the Beaufort Group in South Africa. Trochosuchids are basal therocephalians and are similar in appearance to another primitive group of therocephalians, the Scylacosauridae. Compared to scylacosuchids, trochosuchids have broader snouts and more flattened skulls lacking prominent sagittal crests. They have two enlarged canines on either side of the upper jaw, similar to lycosuchid therocephalians but unlike scylacosuchids, which only have one pair of canines.