Macrotarsomys cf. bastardi Milne-Edwards and G. Grandidier, 1898

The Children’s Cave specimens have been attributed to M. cf. bastardi based on the following characters that allow differentiation from M. koopmani:

● Long incisive foramen ending after the prelobe of M1

● m3 elongated and narrow with no median longitudinal crest between the first and the second lobe of m3 (Figure 4) but presence of an oblique crest ending on the lingual side of the molar.

Attributed material: all from the Upper Stratum: 8 maxillaries; 15 mandibular rami; see Appendix.

The specimens of Children’s Cave display the bunodont molar morphology of Macrotarsomys with round alternate cusps connected medially by a longitudinal crest (Figure 4d,e,g–i). Their m3 allows clear differentiation from M. koopmani because there is never any trace of a longitudinal median link connecting the first and the second lobes. They display some variability in size but compared to the three modern species they correspond to the smallest species, M. bastardi. However, the Children’s Cave specimens display a slight size difference to the modern representatives of this species. The fossil specimens of Children’s Cave are clearly smaller than the larger M. cf. petteri of Andrahomana site (Table 2). There is overlap with Monticolomys koopmani which displays small molars (Figure 5). The few Children’s Cave remains attributed to M. cf. bastardi may belong to a yet undescribed subfossil species, but further revisions of the dental morphology of this species are still needed.