title: Virtual cranial reconstruction of Sahelanthropus tchadensis.
abstract: Previous research in Chad at the Toros-Menalla 266 fossiliferous locality (about 7 million years old) uncovered a nearly complete cranium (TM 266-01-60-1), three mandibular fragments and several isolated teeth attributed to Sahelanthropus tchadensis. Of this material, the cranium is especially important for testing hypotheses about the systematics and behavioural characteristics of this species, but is partly distorted from fracturing, displacement and plastic deformation. Here we present a detailed virtual reconstruction of the TM 266 cranium that corrects these distortions. The reconstruction confirms that S. tchadensis is a hominid and is not more closely related to the African great apes. Analysis of the basicranium further indicates that S. tchadensis might have been an upright biped, suggesting that bipedalism was present in the earliest known hominids, and probably arose soon after the divergence of the chimpanzee and human lineages.
authors.affiliation: Anthropologisches Institut/MultiMedia Laboratorium, Universität Zürich-Irchel, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Christoph P E
authors.initials: CP
authors.lastname: Zollikofer
authors.forename: Marcia S
authors.initials: MS
authors.lastname: Ponce de León
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Lieberman
authors.forename: Franck
authors.initials: F
authors.lastname: Guy
authors.forename: David
authors.initials: D
authors.lastname: Pilbeam
authors.forename: Andossa
authors.initials: A
authors.lastname: Likius
authors.forename: Hassane T
authors.initials: HT
authors.lastname: Mackaye
authors.forename: Patrick
authors.initials: P
authors.lastname: Vignaud
authors.forename: Michel
authors.initials: M
authors.lastname: Brunet
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology; D002596:Chad; D003198:Computer Simulation; D005145:Face / Q000033:anatomy & histology; D005580:Fossils; D049690:History, Ancient; D015186:Hominidae / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D002679:Pan troglodytes / Q000033:anatomy & histology; D010802:Phylogeny; D012886:Skull / Q000033:anatomy & histology*