title: The vertebral column of Australopithecus sediba.
abstract: Two partial vertebral columns of Australopithecus sediba grant insight into aspects of early hominin spinal mobility, lumbar curvature, vertebral formula, and transitional vertebra position. Au. sediba likely possessed five non-rib-bearing lumbar vertebrae and five sacral elements, the same configuration that occurs modally in modern humans. This finding contrasts with other interpretations of early hominin regional vertebral numbers. Importantly, the transitional vertebra is distinct from and above the last rib-bearing vertebra in Au. sediba, resulting in a functionally longer lower back. This configuration, along with a strongly wedged last lumbar vertebra and other indicators of lordotic posture, would have contributed to a highly flexible spine that is derived compared with earlier members of the genus Australopithecus and similar to that of the Nariokotome Homo erectus skeleton.
authors.affiliation: Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY 10003, USA. sawilliams@nyu.edu
authors.forename: Scott A
authors.initials: SA
authors.lastname: Williams
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Ostrofsky
authors.forename: Nakita
authors.initials: N
authors.lastname: Frater
authors.forename: Steven E
authors.initials: SE
authors.lastname: Churchill
authors.forename: Peter
authors.initials: P
authors.lastname: Schmid
authors.forename: Lee R
authors.initials: LR
authors.lastname: Berger
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000033:anatomy & histology; D005580:Fossils; D015186:Hominidae / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D008124:Locomotion; D008159:Lumbar Vertebrae / Q000033:anatomy & histology; D011187:Posture; D012447:Sacrum / Q000033:anatomy & histology; D013019:South Africa; D013131:Spine / Q000033:anatomy & histology* / Q000502:physiology; D013904:Thoracic Vertebrae / Q000033:anatomy & histology