Australopithecus bahrelghazali

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Australopithecus bahrelghazali
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 (KT-12/H1) is a fossil hominin discovered in 1995 by the paleontologist Michel Brunet in the Bahr el Ghazal valley near Koro Toro, in Chad.[1] Named after the valley where it was discovered,[2] Australopithecus bahrelghazali was dated by beryllium-based radiometric dating as living about 3.6 million years ago.[3] 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 locality is roughly 2,500 kilometers west of the East African Great Rift Valley, making it far removed from what broadly thought to be the "cradle" area of human evolution. (The specimen's proper name is KT-12/H1; Brunet named it Abel as a dedication to his deceased colleague Abel Brillanceau.)

The KT-12/H1 mandible has similar features to the dentition of Australopithecus afarensis, which fact has caused researcher William Kimbel to argue that Abel is not a separate species, but "falls within the range of variation" of the species Australopithecus afarensis. By 1996, Brunet and his team classified KT-12/H1 as the holotype specimen for Australopithecus bahrelghazali.[4]This claim is difficult to substantiate, as the describers, contrary to the International Code of Zoological Nomenclature, have kept the specimen locked away from inspection by the general paleoanthropological community.[5] A. bahrelghazali is unique as it is the only australopithecine fossil found in Central Africa. It is also of great importance as it is the first fossil to show that there is a geographical "third window", that is, beyond East Africa and South Africa, of early hominin evolution.[6]

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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. ^ Eugene M., McCarthy (n.d.). "Australopithecus bahrelghazali". Macroevolution.net. Retrieved 8 January 2015. Etymology: Since the type specimen of Australopithecus bahrelghazali was found in the Bahr el Ghazal river valley, its name was created by adding the Latin genitive ending -i to bahrelghazal, yielding bahrelghazali, meaning 'of the Bahr el Ghazal'. 
  3. ^ 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
  4. ^ 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.
  5. ^ 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.
  6. ^ Gibbons, Ann (2007). The First Human. Knopf Doubleday Publishing Group. p. 8. ISBN 0307279820. Retrieved 2015-03-18. 

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