The Sahelanthropus tchadensis is the only known material evidence of the earliest phases of hominid evolution during the Late Miocene (approximately 7 my ago). The skull of the type specimen is virtually complete but badly crushed and deformed. Its reconstruction is fundamental for subsequent analyses of the phyletic relationships of Sahelanthropus with later hominids, earlier hominoids, and extant the Great Apes.
The Sahelanthropus project of the mission paléontologique franco-tchadienne is led by M. Brunet (University of Poitiers, France). The Zurich subproject aims at CT-based data acquisition, computerized reconstruction and morphometric analysis of the Sahelanthropus remains. The heavily mineralized fossil was scanned with a high-resolution industrial tomograph at the Swiss Laboratories for Materials Testing (EMPA) in Zurich. Virtual decomposition into isolated fragments and computer-assisted reconstruction of the cranial morphology, and morphometric comparisons with an extended sample of fossil hominids and Great Apes, is in course.