The tetralophodont pattern of the upper molars in juvenile Cannomys badius (Rodentia, Spalacidae)

Cannomys and Rhizomys are the only living genera of the tribe Rhizomyini (Rhizomyinae, Spalacidae, Rodentia), which is known since the early Late Miocene (at approximately 10 Ma). The dental morphology of all living Rhizomyinae has been already described in detail. However, due to the scarcity of specimens of Cannomys in zoological collections, the teeth of juveniles in this taxon had not been described to date. The study of a specimen of this early age (MNCN 8449) shows that the second upper molars of Cannomys are tetralophodont like those of Rhizomys. One of the assumed differences between Cannomys and Rhizomys, namely the trilophodont second molars of Cannomys, is therefore inaccurate.