Thrinaxodon

Thrinaxodon
Temporal range: Late Permian - Early Triassic,
Fossil of T. liorhinus in National Museum of Natural History
Diagram of skull in lateral view
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Clade: Therapsida
Clade: Cynodontia
Clade: Epicynodontia
Family: Thrinaxodontidae
Watson & Romer, 1956
Genus: Thrinaxodon
Seeley, 1894
Type species
Thrinaxodon liorhinus
Seeley, 1894

Thrinaxodon is an extinct genus of cynodonts which lived in what are now South Africa and Antarctica during the Late Permian - Early Triassic. Thrinaxodon lived just before, during, and right after the Permian–Triassic mass extinction event. It is known from a single species, T. liorhinus.

Similar to other therapsids, Thrinaxodon adopted a semi-sprawling posture, an intermediary form between the sprawling position of basal tetrapods and the more upright posture present in current mammals. Thrinaxodon is prevalent in the fossil record in part because it was one of the few carnivores of its time, and was of a larger size than similar cynodont carnivores. Its survival during the Permian-Triassic extinction event may have been due to its burrowing habits.