The elusive 'second species' in Sterkfontein Member 4: the dental metrical evidence.

Although more than 700 fossil hominid dental specimens recovered from Member 4 of the Sterkfontein Formation have generally been assigned to Australopithecus africanus, it has been suggested that another taxon may be represented in the deposit. Coefficients of variation (CV) of both mesiodistal and buccolingual diameters of the combined dental sample from Sterkfontein (the ‘Sts’ and ‘Stw’ collections) have been compared with those of other fossil hominid species. For some teeth and some diameters, the Sterkfontein sample shows higher CV values than those of other samples, although no consistent pattern seems to be evident. Overall, the descriptive analysis of the CVs does not provide evidence for the existence of a ‘second species’ in the Sterkfontein Member 4 sample.