Skull Sparks Controversy

A new fossil found in Africa just may uproot-and scatter about-the human family tree.

In what's already being hailed as one of the century's most important fossil discoveries, a nearly complete skull unearthed in central Africa may be the earliest human ancestor yet found. Dated at around 7 million years old, the finding, if indeed pre-human, not only pushes back the date when chimpanzees and humans are thought to have evolutionarily gone their separate ways (by at least a million years), but strongly suggests that the earliest ancestors of Homo sapiens did not walk alone.

Michel Brunet of the University of Poitiers in France and his international team, Mission Paléoanthropologique Franco Tchadienne, found the cranium, teeth, and jaw fragments of the primate in the Djurab Desert in northern Chad-far from South Africa and the Rift Valley of East Africa, where humans are largely thought to have evolved.

But even more surprising is the skull's puzzling mix of primitive and advanced characteristics, which is causing a stir of controversy among anthropologists. While its small braincase is apelike, its face and teeth are more human than much younger fossils such as the famous australopithecine Lucy dated at about 3.2 million years old. This doesn't fit into the prevailing linear model of human evolution.

The researchers have nicknamed the fossil Toumai, or "hope of life" in the local Goran language. If future research proves the specimen is indeed an early human, and walked on two legs, then Toumai will surely stand up to today's acclaim and breathe new life into the quest to understand human origins.

Map by Colleen Sudukem

 

The earliest known human ancestor? The new fossil has been given a unique genus and species, Sahelanthropus tchadensis. Courtesy M.P.F.T.
Dr. Michel Brunet comparing Toumai with a chimpanzee skull. Courtesy M.P.F.T.
The Djurab Desert in northern Chad, where researchers unearthed Toumai. Courtesy M.P.F.T.