It wasn't until the discovery of Mrs. Ples that the Transvaal early human fossils were taken seriously. With the discovery of a mature individual, it could no longer be argued that the Taung child, discovered 20 years prior, would have developed into an ape had it lived to maturity. When viewed from the side, Mrs. Ples's face projects forward of the brain case. This is known as prognathism. Recall that Dart proposed the lack of this projection as one trait that differed between the Taung Child and apes. We see in Mrs. Ples that this feature was correctly dismissed by the anatomists of the day, as Mrs. Ples and other A. africanus individuals are strongly prognathic. However, Mrs.Ples also possesses a cranial capacity of 485cc, well above the modern ape average, and has an undeniably forward placed foramen magnum, which would make sense only if she had maintained an erect posture.

Interestingly, several recent studies have suggested that this individual may actually have been a male. (It should be noted, however, that the informal moniker "Mr. Ples" has already been given to a different specimen, Stw 505 -- see: the What'sHot article:1998 #1.)

As a side interest, notice the wedge-shaped portion of the frontal bone that is reconstructed in this cast, and follow the crack around to the rear of the skull. The skull was blown into two pieces during its extraction from the breccia (a hard matrix cemented together by calcium carbonate) when Broom opted to use dynamite to expose the deposits over backbreaking work with a pick-axe. Paleoanthropologists are much more conservation-minded in their excavation techniques today.