Trirachodontidae is an extinct, possibly paraphyletic[1] family of cynognathian cynodonts from the Triassic of China and southern Africa.

Trirachodontids appeared during the Early Triassic soon after the Permian-Triassic extinction event and quickly spread over a wide geographic area in a comparatively brief amount of time from 250 to 237 million years ago.

These burrows were probably used by many individuals to hide from predators, raise young, or stay warm.

Below is a cladogram from Gao et al. (2010) showing the phylogenetic relationships of trirachodontids:[2] Cynognathus Diademodon Trirachodon Langbergia Cricodon Beishanodon Sinognathus Traversodontidae The cladogram above shows a monophyletic Trirachodontidae, but multiple studies have found the family to be paraphyletic with respect to the family Traversodontidae.

[1][4] Below is a cladogram from Hendrickx et al. (2020), who also recovered the members of the subfamily Trirachodontinae as a basal polytomy within the clade Neogomphodontia:[1] Cynognathus Diademodon Titanogomphodon Langbergia Trirachodon Beishanodon Cricodon Sinognathus Traversodontidae