By 2005 experts were closing in on on answer about
whether an ancient skull from Africa belonged to a possible human
ancestor or to a creature which was closer to apes.
Fresh fossil finds from Chad in central Africa, as
well as a new analysis of the skull, seemed to confirm that 'Toumaļ'
was closer to humans. The Toumaļ specimen was unearthed in Chad in
2002 to international acclaim. But rival researchers attacked claims
by the discovery team that it was the oldest hominid, or human-like
The near-complete skull, pieces of jawbone and
several teeth which were unveiled in 2002 were found in the desert
of northern Chad by a team led by Michel Brunet, at the University
of Poitiers, France. At six to seven million years old,
Sahelanthropus tchadensis (better known by its nickname Toumaļ)
dates to about the time at which, according to genetic data, the
ancestors of humans and the ancestors of chimpanzees went their separate
The find had a puzzling combination of modern and
primitive features, with an ape-like brain size and skull shape,
combined with a more human-like face and teeth. It also sported a
remarkably large brow-ridge, more similar to that of hominids.
But at least one anthropologist argued that the fossil could
belong to a female forerunner of the gorilla.
Now in 2005 Brunet and colleagues reported the
discovery of two new jaw fragments and the crown of a tooth in
the same geographical area as the earlier fossils. The authors
stated that their analysis revealed key similarities to hominid
fossils and differences from African apes which supported the
idea that Toumaļ was a hominid.
In a separate paper, a team including Brunet and
Christoph Zollikofer of the University of Zurich in Switzerland,
presented a 3D computer reconstruction of the skull, which had
been badly distorted in the ground.
The team had essentially 'unmangled' the skull,
and the reconstruction apparently confirmed the claim that
tchadensis shared key features with later hominids.
Shown here is the cranium of Sahelanthropus tchadensis,
one of perhaps several species on the human side of the
human-chimpanzee divide which may still have interbred with an
early chimpanzee species at a time at which the two lines were
still very similar - perhaps no more different than modern
humans and Neanderthals who certainly did interbreed (a, facial
view. b, lateral view. c, dorsal view. d, basal view)