Australopithecus bahrelghazali

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Australopithecus bahrelghazali
Conservation status
Fossil
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Subfamily: Homininae
Genus: Australopithecus
Species: A. bahrelghazali
Binomial name
Australopithecus bahrelghazali
Brunet et al., 1995

Australopithecus bahrelghazali is a fossil hominin that was first discovered in 1995[1] by the paleontologist Michel Brunet in the Bahr el Ghazal valley near Koro Toro, in Chad, that Brunet named Abel. It was dated using beryllium-based radiometric dating as living circa 3.6 million years ago.[2]

The find consists of a mandibular fragment, a lower second incisor, both lower canines, and all four of its premolars, still affixed within the dental alveoli. The specimen's proper name is KT-12/H1; "Abel" is the informal name, a dedication to Brunet's deceased colleague Abel Brillanceau. The specimen located roughly 2,500 kilometers west from the East African Great Rift Valley.

The mandible KT-12/H1 discovered has similar features to the dentition of Australopithecus afarensis; this has brought researchers like William Kimbel to argue that Abel is not an exemplar of a separate species, but "falls within the range of variation" of the Australopithecus afarensis. By 1996, Brunet and his team classified KT-12/H1 as the holotype specimen for Australopithecus bahrelghazali.[3] This claim is difficult to substantiate, as the describers have kept KT-12/H1 locked away from the general paleoanthropological community, contrary to the International Code of Zoological Nomenclature 1999.[4] This species is a mystery to some as it is the only australopithecine fossil found in Central Africa. It is also of great importance as it was the first fossil to show that geographically there is a "a third window" of early hominid evolution.

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References[edit]

  1. ^ Brunet, Michel, Beauvilain, Alain, Coppens, Yves, Heintz, Emile, Moutaye, Aladji H.E., and David Pilbeam. 1995 The first australopithecine 2,500 kilometres west of the Rift Valley (Chad).Nature 378: 273-275.
  2. ^ Anne-Elisabeth Lebatard, Didier L. Bourlès, Philippe Duringer, Marc Jolivet, Régis Braucher, Julien Carcaillet, Mathieu Schuster, Nicolas Arnaud, Patrick Monié, Fabrice Lihoreau, Andossa Likius, Hassan Taisso Mackaye, Patrick Vignaud, and Michel Brunet (2008) Cosmogenic nuclide dating of Sahelanthropus tchadensis and Australopithecus bahrelghazali: Mio-Pliocene hominids from Chad. Proc. Nat. Acad. Sci. U.S.A., 105(9): 3226-3231
  3. ^ Brunet, M., A. Beauvilain, Y. Coppens, E. Heintz, A.H.E. Moutaye, and D. Pilbeam. 1996. "Australopithecus bahrelghazali, une nouvelle espece d'Hominide ancien de la region de Koro Toro (Tchad)." In Comptes Rendus des séances de l'Academie des Sciences, vol. 322, pp. 907-913.
  4. ^ Schwartz, Jeffrey H., and Ian Tattersal. 2005 The Human Fossil Record, vol.4: Craniodental Morphology of Early Hominids (Genera Australopithecus, Paranthropus, Orrorin) and Overview. John Wiley and Sons, New Jersey.

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