Brachyuromys betsileoensis (Bartlett, 1880)

Most of the remains attributed to Brachyuromys by Major under the invalid name B. arvicoloides belong to the smaller species B. betsileoensis.

Attributed material: Lower Stratum: 1 maxilla; 1 mandibular ramus. Upper Stratum: 30 crania and maxillary fragments; 44 mandibular rami; 5 molars; see Appendix for details.

The two specimens from the Lower Stratum belong to a juvenile (CD77) and an adult specimen (CD78). They are both small but fit within the variability of the modern B. betsileoensis (Table 1). The other specimens from the Upper Stratum are relatively similar in size to modern representatives but always fit within the smallest dimensions of the bivariate graphs (Figure 3). They display lophs that are less oblique than those of B. ramirohitra and the longitudinal links between lophs are visible until an advanced stage of wear (Figure 4a,b).