Abstract:

Morphological diversity has been revealed in the cranial, mandibular, and dental materials of East Asian Middle Pleistocene hominins, and the taxonomy of later members is uncertain. In order to further apprehend the morphological variability of East Asian Middle Pleistocene hominins and provide evidence for the taxonomy of the later members, the present study conducted three-dimensional morphometric analyses, including morphometric map of lateral enamel thickness and diffeomorphic surface matching of enamel-dentine junction (EDJ), on the lower second molars. The results indicate that: 1) East Asian Middle Pleistocene hominins could be distinguished from both Neanderthals and modern human; 2) East Asian late Middle Pleistocene hominins displayed special distribution pattern of lateral enamel thickness and a more progressive EDJ shape relative to mid-Middle Pleistocene Homo erectus. The present study quantifies two important morphologies and their variability, i.e., distribution pattern of enamel thickness and EDJ shape, in addition to the individual dental traits studied by previous works. It will provide further insight into the taxonomies of East Asian late Middle Pleistocene hominins and help designating isolated teeth from the same period into their correct morphological groups.

Key words: East Asian hominins, Teeth, Dentine, Three-dimensional morphometric