Prothylacynus patagonicus Ameghino, 1891

MACN-A 706 (holotype), left mandibular ramus and the anterior portion of the right ramus fused; MACN 5931, nearly complete skull. Both specimens come from Santa Cruz Province, Argentina; Santa Cruz Formation, Santacrucian SALMA, early Miocene.

Additional information: Sinclair (1906); Cabrera (1927); Marshall (1979).