Australopithecus and the origin of the genus Homo: aspects of biometry and systematics with accompanying catalog of tooth metric data.

Having compiled a new comprehensive catalog of length and breadth measurements of hominid teeth, descriptive and range statistics for the six widely accepted extinct hominid species have been calculated. The analysis supports the Gingerich and Schoeninger hypothesis about tooth variability. There is as least as much differentiation in tooth metrics between A. africanus and A. afarensis as between other hominid taxa commonly accorded distinct species status. A strong biometrical argument emerges for considering A. afarensis a distinct species and more closely related to the genus Homo than A. africanus. Differentiation between taxa inhabiting different geographic regions is indicated and support is provided for Wright's population genetic model for semi-isolated groups.