Correlation of cranial and mandibular prognathism in extant and fossil hominids

Abstract

This pilot study investigates the correlation between mandibular symphysial orientation and both craniofacial and subnasal prognathism in modern humans, chimpanzees, gorillas, and a range of other catarrhine species. The purpose was to assess the potential value of using the degree of prognathism as a parameter that might relate isolated crania and mandibles in the Plio-Pleistocene hominin fossil record of Africa. It is found that angles expressing cranial and mandibular prognathism are intraspecifically correlated in modern humans from pre-industralised populations, but not in the African apes, or interspecifically among catarrhine species. Hominin fossils investigated in this comparative context broadly follow the pattern of correlation shown by modern humans, with some potentially interesting differences that warrant further investigation. In all, the results suggest that the degree of prognathism has little practical value in determining associations between isolated hominin mandibles and crania.