Today’s Top Science Headline: Blockbuster Controversy Unleashed –“One of the Most Provocative Fossils in Human Evolution”




“This specimen is really important. It’s critical,” says Roberto Macchiarelli, a palaeoanthropologist at the University of Poitiers and France's National Museum of Natural History in Paris, who has shared his unpublished report with Nature’s news team. The femur probably belongs to a species called Sahelanthropus tchadensis, he says. The bone is important because it could settle whether the species is the earliest hominin yet found, as its discoverers have claimed after analyzing the skull2. “This is a fantastic occasion to finally tell people what we have, and what we know about this specimen.”

When anthropologists meet in France at the end of January, one of the most provocative fossils in the study of human evolution will not feature on the agenda. The approximately 7-million-year-old femur1 was examined more than a decade ago by scientists in the French city of Poitiers, but has yet to be thoroughly described in a published scientific paper, reports today's journal, Nature.


The fossil may belong to the earliest known hominin, the group that includes humans and their extinct relatives.  Few people have had access to it, but two scientists who analysed the bone briefly in 2004 have prepared a preliminary description of it. They had hoped to present their analysis at the meeting, which is organized by the Anthropological Society of Paris and is taking place in Poitiers. But the proposal by Macchiarelli and Aude Bergeret, director of the Museum of Natural History Victor-Brun in Montauban, France, was rejected by the conference organizers.

The Anthropological Society of Paris told Nature that it had rejected 6 out of 65 abstracts. It said: “This work is conducted by an independent and impartial scientific committee, which is sovereign in its decision. Hence, any accusation about this would not be founded”.

A blockbuster controversy: The Sahelanthropus femur was discovered early on the morning of 19 July 2001 beside a battered skull and other bones at a site in the Djurab Desert in northern Chad, says Alain Beauvilain, a retired geographer who led the field team that made the discovery and who was present at the time.

Michel Brunet, a palaeontologist at the University of Poitiers, who headed the Chadian expedition that discovered the Sahelanthropus remains, argues that the species is the earliest known representative of the hominin lineage.

His team described the skull — dubbed Toumaï, which means 'hope of life' in the Chadian Daza language — in a 2002 Nature paper2 that became a scientific blockbuster. A subsequent analysis of the skull and other fragments by Brunet and his team suggests that Toumaï probably walked upright on two legs3. Brunet declined to comment on the analysis of the thigh bone or on Macchiarelli’s and Bergeret's efforts to describe it at the Poitiers meeting. “Our studies are still in progress,” he wrote in a brief e-mail. “Nothing to say before publishing.”

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The image at the top of the page displays the fossilized skeleton, discovered in Chad in 2001. Researchers have raised questions about its femur (long bone, center right). Alain Beauvilain

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