Australopithecine
The australopithecines, formally Australopithecina or Hominina, are generally any species in the related genera of Australopithecus and Paranthropus. It may also include members of Kenyanthropus, Ardipithecus, and Praeanthropus. The term comes from a former classification as members of a distinct subfamily, the Australopithecinae. They are classified within the Australopithecina subtribe of the Hominini tribe. These related species are sometimes collectively termed australopithecines, australopiths, or homininians. They are the extinct, close relatives of modern humans and, together with the extant genus Homo, comprise the human clade. Members of the human clade, i.e. the Hominini after the split from the chimpanzees, are called Hominina.
While none of the groups normally directly assigned to this group survived, the australopithecines do not appear to be literally extinct as the genera Kenyanthropus, Paranthropus, and Homo probably emerged as sisters of a late Australopithecus species such as A. africanus and/or A. sediba.
The terms australopithecines, et. al., come from a former classification as members of a distinct subfamily, the Australopithecinae. Members of Australopithecus are sometimes referred to as the "gracile australopithecines", while Paranthropus are called the "robust australopithecines".
The australopithecines occurred in the Late Miocene sub-epoch and were bipedal, and they were dentally similar to humans, but with a brain size not much larger than that of modern non-human apes, with lesser encephalization than in the genus Homo. Humans may have descended from australopithecine ancestors and the genera Ardipithecus, Orrorin, Sahelanthropus, and Graecopithecus are the possible ancestors of the australopithecines.
Classification
Classification of subtribe Australopithecina according to.- Australopithecina
- *Australopithecus
- **Australopithecus africanus
- **Australopithecus deyiremeda
- **Australopithecus garhi
- **Australopithecus sediba
- **Australopithecus afarensis
- **Australopithecus anamensis
- **Australopithecus bahrelghazali
- *Paranthropus
- **Paranthropus robustus
- **Paranthropus boisei
- **Paranthropus aethiopicus
- *Ardipithecus
- **Ardipithecus ramidus
- **Ardipithecus kadabba
- *Orrorin
- **Orrorin tugenensis
- *Sahelanthropus
- **''Sahelanthropus tchadensis''
Phylogeny
Physical characteristics
The post-cranial remains of australopithecines show they were adapted to bipedal locomotion, but did not walk identically to humans. They had a forearm to upper arm ratio similar to the Golden Ratio – greater than other hominins. They exhibited greater sexual dimorphism than members of Homo or Pan but less so than Gorilla or Pongo. It is thought that they averaged heights of and weighed between. The brain size may have been 350 cc to 600 cc. The postcanines were relatively large, and had more enamel compared to contemporary apes and humans, whereas the incisors and canines were relatively small, and there was little difference between the males' and females' canines compared to modern apes.Relation to ''Homo''
Most scientists maintain that the genus Homo emerged in Africa within the australopithecines around two million years ago. However, there is no consensus on within which species:Marc Verhaegen has argued that an australopithecine species could have also been ancestral to the genus Pan.
Asian australopithecines
A minority view among palaeoanthropologists is that australopithecines moved outside Africa. One proponent of this theory is Jens Lorenz Franzen, formerly Head of Paleoanthropology at the Research Institute Senckenberg. Franzen argued that robust australopithecines had reached not only Indonesia, as Meganthropus, but also China:In 1957, an Early Pleistocene Chinese fossil tooth of unknown province was described as resembling P. robustus. Three fossilized molars from Jianshi, China were later identified as belonging to an Australopithecus species. However further examination questioned this interpretation; Zhang argued the Jianshi teeth and unidentified tooth belong to H. erectus. Liu et al. also dispute the Jianshi–australopithecine link and argue the Jianshi molars fall within the range of Homo erectus:
However, Wolpoff notes that in China "persistent claims of australopithecine or australopithecine-like remains continue".