Nuchal Crests in Australopithecines

Abstract

THE essential point at issue, which Dr. Robinson contested in his first communication¹, is the general proposition² that the presence of a sagittal crest in the skull of an Old World primate implies the presence of a nuchal (= occipital) crest; and further, that if one of the two is absent, it is usually the sagittal crest. “Unless Paranthropus crassidens is the one exception to a morphogenetic process common to all known Primates”, I therefore suggested that the fact that two presumed female Paranthropus skulls were furnished with high sagittal crests implied that they had also possessed powerful occipital crests and an ape-like planum nuchale. In turn this implied a nuchal musculature and a carriage of the head on the vertebral column of the kind that is seen in the ape. I also suggested that this conclusion was consistent with certain other features of the Australopithecine skull.