Desert Skull Fills Gap in Human Evolution

Article excerpt

Byline: John von Radowitz

A skull belonging to the oldest member of the human family has been unearthed in an African desert.

Christened 'Toumai' by scientists, the creature - thought to be male - lived three million years before the known appearance of any other hominids.

He existed during a crucial gap in human evolution about which virtually nothing is known.

Ten million years ago the world was full of apes. Five million years later the first reliable records of hominids, creatures which are more human than ape, appear.

Sometime in between the human lineage split from that of the chimpanzees, but how and when it happened is a mystery.

Experts yesterday agreed that the find was very significant. However, nobody yet knows whether Toumai is a direct ancestor of modern humans or an early representative of one of the many blind alleys in human evolution. Dr Henry Gee, palaeontology editor at the journal Naturel, which reported the research yesterday, said: 'Toumai is arguably the most important fossil discovery in living memory.'

He said its significance rivalled that of Australopithecus africanus, the first hominid discovered 77 years ago, which confirmed the African origin of humans.

Toumai was found in Chad, central Africa, by an international team carrying out an investigation called the Mission Paleoanthropologique Franco-Tchadienne (MPFT).

The skull, discovered in the vast Djurab desert, was associated with other fossils dating back seven million years to the late Miocene period. At the time, the region was a mixed landscape of lake, desert, forest and grassland.

Toumai, who has been given the scientific name Sahelanthropus tchadensis, had a brain case about the same size and shape of a chimpanzee.

But other features mark him out as human rather than ape. His face was short, and his teeth - especially the canines - were small and human-like.

The skull also has prominent brow ridges, which are a distinctly human hallmark not seen outside our own genus, or species family, Homo.

This could mean that Toumai is a distant direct ancestor of modern humans, but scientists have cautiously avoided the cliche label 'missing link'. …