Several _Australopithecus_ species are known, and they are believed to be the ancestors of the genus _Homo_. The most famous _Australopithecus_ species is _A. afarensis_, known from the 'Lucy' fossil, which is believed to be about 3.2 million years old, discovered in 1974.
The main anatomical features of _Australopithecus_ are:
- Bipedal locomotion: _Australopithecus_ were bipedal, meaning that they walked on two legs.
- Relatively small brain size: The brain size of _Australopithecus_ was relatively small compared to later hominids, but it was larger than that of other apes.
- Prognathic facial structure: Australopithecus had a prognathic facial structure, meaning that the upper jaw was forward of the lower jaw.
- Large teeth: _Australopithecus_ had relatively large teeth, especially their molars, which were adapted for eating a variety of plant foods.
_Australopithecus_ is considered an important link between modern humans and the common ancestor of humans and apes. The discovery of _Australopithecus_ fossils has helped to fill in gaps in our understanding of human evolution.