Australopithecus africanus - Raymond Dart's baby

Australopithecus africanus The Taung Child Specimen - Raymond Dart's Baby Photo: Guérin Nicolas

"Mrs. Ples" (click to enlarge) Photo: Luna04

A. africanus is known only from nw South Africa

Dart with Taung skull

Dart (1925) immediately claimed the specimen represented a very early human ancestor. The scientific establishment, however, long rejected his claim. Accepted wisdom at the time said humans had come into being in Asia.

"Mrs. Ples" — superior aspect Photo: Guérin Nicolas

Taung Child: Beak gouges? (click to enlarge) Photo: Lee Berger

The most complete skull of an Australopithecus africanus adult ever found (dating to 2.15 mya), a specimen (STS 5) nicknamed "Mrs. Ples"^† (see figure at right), was discovered in 1947 by Dart's friend, Robert Broom and John T. Robinson at Sterkfontein (see figure below right). Ples is short for Plesianthropus, the defunct genus to which the skull was originally assigned. Many additional Australopithecus africanus fossils continue to be found at Sterkfontein (see picture of excavation), but no others have ever been found at Taung, despite intensive search.

In a recent paper (Berger 2006), paleontologist Lee Berger provides strong evidence that marks in the eye sockets of the Taung Child are damage caused by birds of prey. The study shows it's likely that an eagle brought the child to the site where the skull was discovered, and that this is the reason for the absence of other australopithecine remains at Taung. The marks that have been interpreted as beak damage caused when eagles ripped out the unfortunate child's eyes are indicated in the figure at left.

Similar to its northern precursor, Australopithecus afarensis, which is known from east Africa, Australopithecus africanus was bipedal with arms a bit longer than its legs. Both were gracile australopithecines with relatively slender builds.

Australopithecus africanus had a cranial capacity of about 450 cc, a brain size that puts it on a par with a rather brainy modern chimpanzee.

Experts who argue Australopithecus africanus was an ancestor of modern humans say it was somewhat more humanlike with respect to cranial characteristics than was Australopithecus afarensis. However, it also had apelike traits such as curved fingers suited for climbing trees. Such simian features suggest to some researchers that A. africanus evolved into Paranthropus robustus, one of the robust autralopithecines, not Homo.

However — whether the facts are consistent with the idea that australopithecines were direct ancestors of humans or not — Raymond Dart's work, together with that of Robert Broom and the Leakeys, succeeded in convincing the scientific world that Darwin had been right in asserting humankind had its origins in Africa.

The focus remains on that continent today, though the exact role of the australopithecines in human evolution has yet to be resolved.