Pascualgnathus is an extinct genus of traversodontid cynodonts from the Middle Triassic of Argentina.

Fossils have been found from the Río Seco de la Quebrada Formation of the Puesto Viejo Group.

The postcanine teeth of Pascualgnathus and other traversodontids are wide, allowing them to eat plant material.

[2] When Pascualgnathus was first named in 1966, it was considered a member of the family Diademodontidae more closely related to the African genus Trirachodon than the South American genus Diademodon.

[1][3] Diademodon was later uncovered from the Río Seco de la Quebrada Formation alongside Pascualgnathus, suggesting that the ancestors of Pascualgnathus migrated from Africa to South America.