Myocastorini

Myocastorini is a tribe of echimyid rodents, proposed in 2017, and containing the five extant genera Callistomys, Hoplomys, Myocastor, Proechimys, and Thrichomys.

Definition

Myocastorini members share long upper incisor roots, and mid- to long-sized lower incisor roots. These five genera share either four or five lophids on the lower deciduous fourth premolar, three roots anchoring the upper molars, and well-connected lophs on cheek teeth.
Members display a variety of lifestyles including terrestrial, arboreal, and amphibious adaptations.

Phylogeny

On the one hand, the genus Proechimys is the sister group to the genus Hoplomys, and both form a clade of lowland rainforest terrestrial spiny rats. On the other hand, Callistomys is the sister group to Myocastor. In turn, these two pairs of genera share evolutionary affinities with Thrichomys.