Phenetic affinities among earlyHomocrania from East and South Africa

Abstract

A quantitative analysis that employs randomization methods and distance statistics has been undertaken in an attempt to further clarify the phenetic and taxonomic affinities of Plio-PleistoceneHomocrania from eastern and southern Africa. Modern reference samples ofHomo sapiens(n=44),Pan troglodytes(n=50) andGorilla gorilla(n=50), and threeParanthropuscrania were employed in an assessment of the differences among the earlyHomospecimens. Crania attributed toHomo habilis sensu lato(OH 24, KNM-ER 1470, KNM-ER 1813, Stw 53 and SK 847) are clearly distinct from those assigned toHomo ergasteror earlyHomo erectus(KNM-ER 3733 and KNM-WT 15000). The crania attributed toH. habilis sensu latoform three rather distinct phenetic clusters. An orthognathic reconstruction of KNM-ER 1470 is clearly differentiated from the other four specimens principally by virtue of its size, whereas significant shape differences exist between the smaller specimens from eastern Africa (OH 24 and KNM-ER 1813) and those from South Africa (SK 847 and Stw 53). The level of taxonomic differentiation between these three clusters is difficult to assess on the basis of the data employed here, but these results lend support to arguments that KNM-ER 1470 should be attributed to a different species from OH 24 and KNM-ER 1813, and to suggestions that the South African specimens may represent a species ofHomothat has not been sampled in eastern Africa. Furthermore, the present data indicate that gorillas do not comprise an appropriate group by which to gauge intraspecific cranial variability in earlyHomo.