title: External and internal morphology of the BAR 1002'00 Orrorin tugenensis femur.
abstract: Late Miocene fossils from the Lukeino Formation in Kenya's Tugen Hills are assigned to Orrorin tugenensis. Of 20 fossils recovered there to date, 3 are proximal femurs. One of these, BAR 1002'00, preserves an intact head connected to the proximal shaft by an elongated neck. Although this fossil is comparable in size to Pan troglodytes, computerized tomography scans of the neck-shaft junction of BAR 1002'00 reveal that the cortex is markedly thinner superiorly than inferiorly, differing from the approximately equal cortical thicknesses observed in extant African apes, approaching the condition in later hominids, and indicating that O. tugenensis was bipedal.
authors.affiliation: Orthopedic Biomechanics Laboratory, Allegheny General Hospital, Pittsburgh, PA 15212, USA.
authors.forename: K
authors.initials: K
authors.lastname: Galik
authors.forename: B
authors.initials: B
authors.lastname: Senut
authors.forename: M
authors.initials: M
authors.lastname: Pickford
authors.forename: D
authors.initials: D
authors.lastname: Gommery
authors.forename: J
authors.initials: J
authors.lastname: Treil
authors.forename: A J
authors.initials: AJ
authors.lastname: Kuperavage
authors.forename: R B
authors.initials: RB
authors.lastname: Eckhardt
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005269:Femur / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005272:Femur Neck / Q000033:anatomy & histology; D005580:Fossils; D015186:Hominidae / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D007630:Kenya; D008124:Locomotion; D008953:Models, Anatomic; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D010802:Phylogeny; D011187:Posture; D014057:Tomography, X-Ray Computed