Australopithecine

Australopithecina or Hominina is a subtribe in the tribe Hominini. The members of the subtribe are generally ''Australopithecus'' (cladistically including the genera ''Homo'', '' Paranthropus'', and ''Kenyanthropus''), and it typically includes the earlier ''Ardipithecus'', ''Orrorin'', ''Sahelanthropus'', and ''Graecopithecus''. All these closely related species are now sometimes collectively termed australopiths or homininians. They are the extinct, close relatives of humans and, 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 now called Hominina (''see Hominidae; terms "hominids" and hominins'').

While none of the groups normally directly assigned to this group survived, the australopiths do not appear to be literally extinct (in the sense of having no living descendants) as the genera ''Kenyanthropus'', ''Paranthropus'' and ''Homo'' probably emerged as sister of a late ''Australopithecus'' species such as '' A. africanus'' and/or '' A. sediba''.

The term australopithecine came from a former classification as members of a distinct subfamily, the Australopithecinae. Members of ''Australopithecus'' are sometimes referred to as the "gracile australopiths", while ''Paranthropus'' are called the "robust australopiths".

The australopiths 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 (genus ''Homo'') may have descended from australopith ancestors and the genera ''Ardipithecus'', ''Orrorin'', ''Sahelanthropus'', and ''Graecopithecus'' are the possible ancestors of the australopiths.

Classification

Classification of subtribe Australopithecina according to .
*Australopithecina
**''Australopithecus''
***'' Australopithecus africanus''
***'' Australopithecus deyiremeda''
***''Australopithecus garhi''
***'' Australopithecus sediba''
***'' Australopithecus afarensis'' (=''Praeanthropus afarensis'')
***''Australopithecus anamensis'' (=''Praeanthropus anamensis'')
***''Australopithecus bahrelghazali'' (=''Praeanthropus bahrelghazali'')
**'' Paranthropus''
***'' Paranthropus robustus''
***'' Paranthropus boisei''
***''Paranthropus aethiopicus''
**''Ardipithecus''
***''Ardipithecus ramidus''
***'' Ardipithecus kadabba''
**''Orrorin''
***''Orrorin tugenensis''
**''Sahelanthropus''
***'' Sahelanthropus tchadensis''
**''Graecopithecus''
***'' Graecopithecus freybergi''
***'' Graecopithecus macedoniensis''

Phylogeny

Phylogeny of Hominina/Australopithecina according to Dembo ''et al''. (2016).

Physical characteristics

The post-cranial remains of australopiths show they were adapted to bipedal locomotion, but did not walk identically to humans. They have a high brachial index (forearm/upper arm ratio) when compared to other hominins, and they exhibit 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 (the teeth behind the canines) 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 Australopiths around two million years ago. However, there is no consensus on within which species:

Asian australopiths

A minority-held view among palaeoanthropologists is that australopiths moved outside Africa. A notable proponent of this theory is Jens Lorenz Franzen, formerly Head of Paleoanthropology at the Research Institute Senckenberg. Franzen argues that robust australopiths 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 (Longgudong Cave) were later identified as belonging to an ''Australopithecus'' species. However further examination questioned this interpretation; Zhang (1984) argued the Jianshi teeth and unidentified tooth belong to ''H. erectus''. Liu ''et al''. (2010) also dispute the Jianshi-australopithecine link and argue the Jianshi molars fall within the range of '' Homo erectus'':

But, Wolpoff (1999) notes that in China "persistent claims of australopithecine or australopithecine-like remains continue".

See also

* ''Dawn of Humanity'' (2015 PBS film)
* Human taxonomy
* Human timeline

Notes

References

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External links

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Informative lecture on ''Australopithecines''

{{DEFAULTSORT:Australopithecine

Human evolution
Pliocene
Hominini