Xenorhinotherium was named by Cartelle and Lessa (1988) [Diagnosis: Similar in size to M. patachonica. Rostrum sharp and slightly recurved ventrally. External nares more caudal in position than in M. patachonica. Post-nasal fossae in frontal position, double, concave and with smooth surface. Basisphenoid wings ampular and fenestrate at the mesial facet. Palatine foramina in caudal position, localed at the level of upper M2. Palate with angular configuration, with oval rostral margin. Mandible with rostral region oval in shape. Mandibular symphisis starting at the level of the canines. Lower P4 larger in length than lower M1 and with entolophid; lower M1 and M2-3 lacking entolophid in a comparable way as in M. patachonica. Cervical, toracic and lumbar vertebrae similar to those in M. patachonica, but main body less robust. Apendicular skeleton similar to that of M. patachonica, but with alar process of the radius less marked and more gracile metapodial.]. Its type is Xenorhinotherium bahiense.

It was assigned to Macraucheniidae by Salles et al. (2006); and to Macraucheniinae by Schmidt and Ferrero (2014).