In commemoration of P. V. Tobias’s 80th birthday, and the 80th year since Dart published his paper on Taung, newer studies on chimpanzee brains and newer fossil discoveries (e.g. Hadar 162–28, StW 505) make it appropriate to re-assess Dart’s original contribution. The matter of where to place the lunate sulcus has been a controversial issue, but the contrast between the Taung child’s endocast morphology, and that of pongids, particularly the chimpanzee, as well as the clear-cut lunate sulcus in a posterior position of StW 505 indicate that Dart was indeed right, and that the brain of australopithecines was reorganised prior to any size increase in endocranial volume. This reorganisation involved a relative increase in posterior parietal association cortex, the flip-side, as it were, of a relative reduction in primary visual striate cortex. It is most probable that the changes in cerebral organisation were an adaptive response to changing and expanding ecological opportunities for these early hominids. The latter development of any major size increase of the whole brain had to await the evolution of Homo lineages. Clearly, from at least three million years ago, the evolution of the hominid brain has been a mosaic process of both size increases, allometric and non-allometric, as well as critical reorganisational changes, of which the posterior placement of the lunate sulcus is proof of that change, which Dart had already appreciated in 1924–5.