Intraspecific variation in molar topography of the early Eocene stem primate Microsyops latidens (Mammalia, ?Primates)

Variation in postcanine teeth is relevant to answering questions about both taxonomy and diet. In such contexts, understanding the patterns and the amounts of variation present in a single species is fundamentally important. Here we use dental topographic analysis (DTA) to study variation in functional aspects of the lower second molar (n = 51) and lower fourth premolar (n = 41) in a large, stratigraphically controlled sample of the early Eocene stem primate Microsyops latidens, which permits study of fine scale variation through time in a single species, during a period of notable climatic change. To contextualize variation in M. latidens, we used DTA to study extant euarchontan taxa, representing three orders and seven families (n = 96). Previous study of M. latidens suggested that it was highly variable in size and lower molar morphology, potentially giving rise to later species of microsyopids. However, comparison with extant taxa suggests that the dental form of M. latidens shows low levels of intraspecific variation. The dental topography of M. latidens also does not reflect the previously postulated taxonomic split. Our results suggest instead that M. latidens likely did not undergo change in dental topography consistent with a shift in either dietary adaptive niche or ecospace. Taken together, our results suggest low levels of variation in dental form and potentially diet of M. latidens, indicating that this taxon likely remained within a single adaptive zone.

Duke Scholars

Author Keegan Rayne Selig Evolutionary Anthropology