The first australopithecine was found by Professor Raymond Dart in 1924, in limestone rock from a place called Taung in South Africa. Embedded in one of the rocks were the remains of a cranium. Dart was certain it was an extinct hominid, and finally settled for naming it Australopithecus africanus, the first of the "gracile" australopithecines, hominids with a slender or graceful physique.

In 1936, at the nearby site of Sterkfontein, in theTransvaal, Robert Broom found another skull of an adult female that he attributed immediately to Australopithecus, thoughinitially to a different species. Eventually, it too was assigned to Australopithecus africanus. After World War II, more remains of a similar kind were found at Makapansgat in South Africa. These too have been assigned to A. africanus but the dating of these South African specimens has been difficult.

The second gracile australopithecine was recognised by Johanson and White in 1978 as Australopithecus afarensis from evidence at Hadar, Ethiopia and Laetoli, Tanzania. More remains have since been found at other East African sites. Material from Ethiopia alone represents some 65 individuals, including the partial skeleton known as "Lucy" from Hadar.

A. afarensis was thought to be the oldest known hominid species before the recent discovery of A. ramidus.