Lovejoy C Owen, Latimer Bruce, Suwa Gen, Asfaw Berhane, White Tim D
Department of Anthropology, School of Biomedical Sciences, Kent State University, Kent, OH 44240, USA.
Science. 2009 Oct 2;326(5949):72e1-8.
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.
拉密达地猿足部的几个元素得以保存，主要保存在ARA-VP-6/500部分骨架中。该足部有一个向外大幅展开的大脚趾，在陆地两足行走时不具有推进作用。然而，它缺乏现存非洲猿类中高度特化的跗跖关节松弛和内翻，而这种松弛和内翻在垂直攀爬时能使足部与基质最大限度地贴合。相反，它表现出一些原始特征，从足放平到离地推蹬阶段都能保持足底的刚性，这让人联想到一些中新世猿类和旧世界猴。此外，腓骨长肌的作用更类似于旧世界猴的同源肌肉，而非非洲猿的。指骨长度与大猩猩的最为相似。因此，拉密达地猿的步态模式在已知灵长类中是独一无二的。所以，人类和黑猩猩的最后共同祖先乃是一个谨慎的攀爬者，保留了对树上跖行的适应性。
