Known as one of the earliest direct human ancestors, A. africanus was a member of the larger group gracile Australopithecines and the genus Australopithecus.
Literally meaning "southern ape from Africa", the first example of this species was found by Raymond Dart from the University of the Witwatersrand in November of 1924. Recovered from southwest of Johannesburg was most of the skull, the complete lower jaw and a brain endocast.
Many features distinguish this species from its predecessor A. afarensis. Though both possessed the lighter builds common to members of gracile Australopithecines,1 A. africanus' facial features differed greatly. With a higher forehead, less prominent brow ridges and a shorter face, this species began to develop more human-like traits. The sexual dimorphism exhibited in A. afarensis was most likely less prominent here. Bipedalism was evident by the central position of the foramen magnum, and by the anatomy of the post cranial skeleton.
A. africanus had a brain capacity of approximately 500 cm3. Though radiometic dating is difficult under the sort of terrain in which they where distributed, its estimated dates are from about 3.5 to 2.5 million years ago and it ranged across southern Africa.
After Dart's publication of his work in early 1925, the Scottish paleontologist Robert Broom joined his team. Together, they discovered several similar fossils to A. africanus, yet more robust in shape. They decided to group these fossils under the seperate species name Australopithecus robustus.
1 As mentioned in the Australopithecus node, A. afarensis is sometimes grouped under robust Australopithecines, despite its relatively lighter frame.