Brain Shape Confirms Controversial Fossil as Oldest Human Ancestor

A seven-million-year-old skull found in the Djurab Desert in Chad may indeed represent the earliest known member of the human family. Researchers unveiled the specimen back in 2002 and made quite a splash with their claim that the ancient fossil was our ancestor. They assigned it to a new species, Sahelanthropus tchadensis (nickname: Toumaï) and said it was very close to the point at which the human lineage diverged from that of our closest living relative, the chimpanzee. Critics, however, countered that the skull was probably an ape’s instead of that of a hominin (a creature on the line leading to us), given its primitive features. But a new analysis of the skull—specifically, its braincase—supports the discoverers’ claim that Toumaï is a hominin.

Thibaut Bienvenu of the Collège de France and his colleagues reconstructed Toumaï’s endocast—a cast of the interior of the braincase, [...] Scientific American

Actualización 07-04-13. La forma interna del cráneo de Toumaï lo confirma como un antepasado humano
... Thibaut Bienvenu, del Colegio de Francia, y sus colegas, reconstruyeron el endocasto de Toumaï, es decir, el molde interior del cráneo, el cual revela la forma del cerebro. Debido a que el cráneo fósil está distorsionado y lleno de una matriz altamente mineralizada, tuvieron que hacer su reconstrucción virtual, lo que significa que se hizo mediante imágenes de microtomografía de rayos X 3D sincrotrón, y luego introduciendo esos datos en un programa que les permitió retirar la matriz y corregir la distorsión en la pantalla...