Cosmogenic nuclide dating of sahelanthropus tchadensis online beta dating sites

Existing fossils include a relatively small cranium named Toumaï ("hope of life" in the local Daza language of Chad in central Africa), five pieces of jaw, and some teeth, making up a head that has a mixture of derived and primitive features.

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However, because no postcranial remains (i.e., bones below the skull) have been discovered, it is not known definitively whether Sahelanthropus was indeed bipedal, although claims for an anteriorly placed foramen magnum suggests that this may have been the case.

Upon examination of the foramen magnum in the primary study, the lead author speculated that a bipedal gait "would not be unreasonable" based on basicranial morphology similar to more recent hominins.

Some palaeontologists have disputed this interpretation, stating that the basicranium, as well as dentition and facial features, do not represent adaptations unique to the hominin clade, nor indicative of bipedalism; The fossils were discovered in the Djurab Desert of Chad by a team of four led by a Frenchman, Alain Beauvilain, and three Chadians, Adoum Mahamat, Djimdoumalbaye Ahounta, and Gongdibé Fanoné, members of the Mission paleoanthropologique Franco-tchadienne led by Michel Brunet.

All known material of Sahelanthropus was found between July 2001 and March 2002 at three sites: TM 247, TM 266, which yielded most of the material, including a cranium and a femur, and TM 292. tchadensis is the oldest known human ancestor after the split of the human line from that of chimpanzees.

The bones were found far from most previous hominin fossil finds, which are from Eastern and Southern Africa. Sahelanthropus may represent a common ancestor of humans and chimpanzees, though no consensus has been reached yet by the scientific community.

However, an Australopithecus bahrelghazali mandible was found in Chad by Mamelbaye Tomalta, Najia and Alain Beauvilain, Michel Brunet and Aladji H. The original placement of this species as a human ancestor but not a chimpanzee ancestor would complicate the picture of human phylogeny.

In particular, if Toumaï is indeed a direct human ancestor, then its facial features bring into doubt the status of Australopithecus whose thickened brow ridges were reported to be similar to those of some later fossil hominins (notably Homo erectus), and where the brow ridge morphology of Sahelanthropus differs from that observed in all australopithecines, most fossil hominins and extant humans.

Another possibility is that Toumaï is related to both humans and chimpanzees, but is the ancestor of neither.

Brigitte Senut and Martin Pickford, the discoverers of Orrorin tugenensis, suggested that the features of S.

tchadensis are consistent with a female proto-gorilla.

Even if this claim is upheld the find would lose none of its significance, because at present, very few chimpanzee or gorilla ancestors have been found anywhere in Africa. tchadensis is an ancestral relative of the chimpanzees or gorillas, then it represents the earliest known member of their lineage. tchadensis does indicate that the last common ancestor of humans and chimpanzees is unlikely to closely resemble extant chimpanzees, as had been previously supposed by some paleontologists.

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