The recovery of an almost complete skull and partial associated mandible of Catonyx tarijensis from Puerto Arazatí, Department of San José, is the first record of this species from Uruguay. Catonyx tarijensis is only known from the Ensenadan land mammal age. Mammals from multiple land mammal ages have been recovered from the San José formation and suggest that it is time transgressive and may range in age from the Montehermosan to the Ensenadan.