Thylacosmilus atrox Riggs, 1933

FMNH P14531 (holotype), nearly complete skull ( Chiquimil locality, Catamarca Province, Argentina; Corral Quemado Formation, Chapadmalalan Stage/Age, late Pliocene ; FMNH P143344 (paratype): left mandibular ramus with dentition ( Chiquimil locality, Catamarca Province, Argentina; Andagala Formation, Huayquerian Stage/Age, late Miocene) ; MLP 65-VII-29-41, partial skull, partial right mandibular ramus with dentition and a fragment of the right upper canine isolated ( Salinas Grandes de Hidalgo, La Pampa Province, Argentina; Cerro Azul Formation, Huayquerian Stage/Age, late Miocene) .

Additional information: Riggs (1934); Goin & Pascual (1987); Forasiepi et al. (2019).

Comment: The FMNH specimens were revised in photographs provided by A. Forasiepi.