See where Australopithecus exists on this
Evolution History Map
The Australopithecus 450-500cc brain size is a little larger than a gorrila's. In terms of brain-to-body ratio, they are midway between apes and humans. Below shows the ape-like hand of the species.

First discovered in 1929, by Raymond Dart, Australopithecus is the longest surviving hominid species in the evolution tree, spanning over 3 million years from 4 million to 1 million years ago. There are several different branches on the Australopithecus tree that includes Australopithecus africanus, robustus, bosei, aethiopicus, afarensis, anamensis and ramidus. Most of these branches in Australopithecus's evolution were a dead end which lead to no further descendants. Anthropologists speculate these branches died out due to fierce competition with preditors.

It has also been speculated based on recent evidence, that Australophithecus africanus created very crude stone tools, but it is also believed they adapted this tool making skill from another species of hominid.

In 1974, a world awakening discovery was uncovered by paleoanthropologist Donald Johanson of a remarkable and miraculous upright skeleton of Australopithecus afarensis, forever coined as "Lucy". It is the best preserved skeleton of any erect walking human ever found which prompted a reevaluation of previous evidence for human origins. To many, Lucy is considered the "mother of all humankind", and to others she is "the woman who shook up man's family tree". Other more complete and older fossils have since been found, however Lucy still remains reference point to which other discoveries are compared.

Though the Australopithecus afarensis lineage is considered an ascendant to Homo, the species did not have two half brains that would come millions of years later in another species of hominid.

Photos - California Academy of Sciences,
(Exhibition - August, 1999)

From Lucy to Language, Donald Johanson & Blake Edgar,
Simon & Schuster, 1996