The term australopithecine refers generally to any species in the related genera Australopithecus (some of which are sometimes placed in Praeanthropus) and Paranthropus (sometimes synonymized with Australopithecus). This may also include Kenyanthropus. These genera occurred in the Plio-Pleistocene era, and were bipedal and dentally similar to humans, but with a brain size not much larger than modern apes, with lesser encephalization than in the genus Homo.
They are classified within the Australopithecina subtribe of the Hominini tribe. They appeared in the Pliocene:
- Australopithecus, appeared about 4 million years ago;
- Kenyanthropus, appeared about 3.5 million years ago.
- Paranthropus, appeared about 2.7 million years ago.
When used alone, the term refers to these genera together. Australopithecus is sometimes referred to as the "gracile (slender) australopithecines", while Paranthropus are also called the "robust australopithecines".
A possible ancestor of the australopithecines is the genus Ardipithecus, which lived in East Africa. The genus Homo (humans, which appear about 2.4 million years ago with Homo habilis) may be descended from australopithecine ancestors.