title: Combining prehension and propulsion: the foot of Ardipithecus ramidus.
abstract: Several elements of the Ardipithecus ramidus foot are preserved, primarily in the ARA-VP-6/500 partial skeleton. The foot has a widely abducent hallux, which was not propulsive during terrestrial bipedality. However, it lacks the highly derived tarsometatarsal laxity and inversion in extant African apes that provide maximum conformity to substrates during vertical climbing. Instead, it exhibits primitive characters that maintain plantar rigidity from foot-flat through toe-off, reminiscent of some Miocene apes and Old World monkeys. Moreover, the action of the fibularis longus muscle was more like its homolog in Old World monkeys than in African apes. Phalangeal lengths were most similar to those of Gorilla. The Ardipithecus gait pattern would thus have been unique among known primates. The last common ancestor of hominids and chimpanzees was therefore a careful climber that retained adaptations to above-branch plantigrady.
authors.affiliation: Department of Anthropology, School of Biomedical Sciences, Kent State University, Kent, OH 44240, USA.
authors.forename: C Owen
authors.initials: CO
authors.lastname: Lovejoy
authors.forename: Bruce
authors.initials: B
authors.lastname: Latimer
authors.forename: Gen
authors.initials: G
authors.lastname: Suwa
authors.forename: Berhane
authors.initials: B
authors.lastname: Asfaw
authors.forename: Tim D
authors.initials: TD
authors.lastname: White
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005002:Ethiopia; D005528:Foot / Q000033:anatomy & histology*; D005529:Foot Bones / Q000033:anatomy & histology*; D005580:Fossils; D005684:Gait; D015186:Hominidae / Q000033:anatomy & histology* / Q000502:physiology*; D008124:Locomotion; D008682:Metatarsal Bones / Q000033:anatomy & histology; D013628:Talus / Q000033:anatomy & histology; D013639:Tarsal Bones / Q000033:anatomy & histology; D013710:Tendons / Q000033:anatomy & histology; D050277:Toe Phalanges / Q000033:anatomy & histology; D016138:Walking