Two- and three-dimensional computer imaging shows that endocranial cap
acity in an similar to 2.8- to 2.6-million-year-old early hominid cran
ium (Stw 505) from Sterkfontein, South Africa, tentatively assigned to
Australopithecus africanus, is similar to 515 cubic centimeters. Alth
ough this is the largest endocranial capacity recorded for this specie
s, it is still markedly less than anecdotal reports of endocranial cap
acity exceeding 600 cubic centimeters. No australopithecine has an end
ocranial capacity approaching, let alone exceeding, 600 cubic centimet
ers. Some currently accepted estimates of early hominid endocranial ca
pacity may be inflated, suggesting that the tempo and mode of early ho
minid brain evolution may need reevaluation.