Australopithecus

Australopithecus (/ˌɒstrələˈpɪθɪkəs, -loʊ-/ OS-trə-lo-PITH-i-kəs;[1] from Latin australis, meaning 'southern', and Greek πίθηκος (pithekos), meaning 'ape', informal australopithecine or australopith (although the term australopithecine has a broader meaning as a member of the subtribe Australopithecina, [2][3] which includes this genus as well as the Paranthropus, Kenyanthropus,[4] Ardipithecus,[4] and Praeanthropus genera) [5] is a genus of hominins. From paleontological and archaeological evidence, the genus Australopithecus apparently evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct two million years ago. Australopithecus is not literally extinct (in the sense of having no living descendants) as the Kenyanthropus, Paranthropus and Homo genera probably emerged as sister of a late Australopithecus species such as Australopithecus africanus and/or A. sediba. During that time, a number of australopithecine species emerged, including ''Australopithecus afarensis, A. africanus, A. anamensis, A. bahrelghazali, A. deyiremeda (proposed), A. garhi, and A. sediba''.

For some other hominid species of this time – A. robustus, A. boisei and A. aethiopicus – some debate exists whether they truly constitute members of the genus Australopithecus. If so, they would be considered 'robust australopiths', while the others would be 'gracile australopiths'. However, if these more robust species do constitute their own genus, they would be under the genus name Paranthropus, a genus described by Robert Broom when the first discovery was made in 1938, which makes these species P. robustus, P. boisei and P. aethiopicus.

Australopithecus species played a significant part in human evolution, the genus Homo being derived from Australopithecus at some time after three million years ago. In addition, they were the first hominids to possess certain genes, known as the duplicated SRGAP2, which increased the length and ability of neurons in the brain.[6] One of the australopith species evolved into the genus Homo in Africa around two million years ago (e.g. Homo habilis), and eventually modern humans, H. sapiens sapiens.[7]

In January 2019, scientists reported that A. sediba is distinct from, but shares anatomical similarities to, both the older A. africanus, and the younger H. habilis.[8]