A large, intact primate skull, more than six million years old, has been found in Chad and may provide another piece in the rapidly expanding jigsaw puzzle of pre-human history.
Although the skull has not yet been positively identified as that of hominid, or pre-human creature, the size of the cranium suggests it is more likely to be an ancestor of humanity than an early great ape.
If this finding is confirmed, the map and the time-lines of human evolution may have to be revised. The skull, found by a Franco-Chadian team in the Djourab desert of northern Chad last month, is twice as old as "Lucy", the fossilised hominid found in Ethiopia in 1974, now thought to be a near-relation, rather than a direct ancestor, of Homo sapiens.
The Chadian skull is roughly the same age as the Millennium Ancestor, or Orrorin tugenensis, the new species of hominid more modern in its characteristics than Lucy and discovered by a Franco-British team in Kenya last year. The significance of the find is two-fold. It is unusual to discover a near-complete skull, even two or three million years old, never mind six million years old.
Most of the earliest pre-human remains have been discovered to the east of the African Rift Valley. The new skull was far to the west. The lower jaw of a hominid creature, named "Abel", thought to be 3.5 million years old, was found in Chad six years ago. The theory that the cradle of humanity lies to the east of the Rift Valley may now have to be reconsidered. The opening of the rift, eight million years ago, is thought to have changed the ecology of Africa, leaving jungle on the west, and savannah or grassland on the east.
Anthropologists believe the first pre-humans began to walk on two legs to adapt to their grassland habitat. If the Chadian skull is found to be that of a pre-human creature, this concept will have to be abandoned or comprehensively reworked. Baba Elhadj Mallah, the director of the Chadian national research centre, told the French paper Le Figaro that the skull was "dark, entirely fossilised. The cranium is very large and the teeth very developed."
Professor Michel Brunet, the paleontologist from the University of Poitiers in charge of the excavations in Chad (and the man who found Abel) had hoped to keep the discovery secret until he publishes his scientific findings next year. But the news was given to the media in Chad last week.
The French ambassador to Chad, Jacques Courbin, refused to give details but said the skull appeared to be an extremely important find. "It's very moving to hold such an object," he said. "For a scientist, it's like the Holy Grail."Reuse content