This feature is clearly the result of differential patterns of bone growth (e.g., increased osteoblast activity in the region of the foramen and/or increased osteoblast activity anterior to it) and is likely associated with mandibular robusticity requirements. The same character definitions and character state allocations provided by Strait et al. (1997) and Strait and Grine (2001) are followed for the fossil hominins. The primitive character state is seen in Kenyapithecus, Dryopithecus, Graecopithecus, Pongo, Gorilla, Pan, Ardipithecus, the "anamensis group," and Praeanthropus, in that there is distinct hollowing within the external bone table, above and behind the mental foramen (= 0). Australopithecus and K. rudolfensis show variability in the development of this feature; intra-specifically (= 1), P boisei, P. robustus, H. habilis, H. ergaster, and H. sapiens are defined by the absence of such a hollow.
Was this article helpful?