image: Inferred locomotor behaviors of Sterkfontein hominin specimens StW 311 (top) and StW 522 (bottom) based on bone volume fraction distribution view more
Credit: Image credit: Leoni Georgiou.
Researchers report evidence of diverse modes of locomotion in fossil hominins. Bipedalism is a key development in the evolution of modern humans, but where bipedalism emerged in the hominin lineage remains a source of debate. To reconstruct locomotor behavior in fossil hominins, Leoni Georgiou and colleagues compared the structure of trabecular bone--the porous bone inside the ends of long bones--from the femoral heads of two fossil hominins from the Sterkfontein Caves in South Africa with that of humans and nonhuman great apes. One fossil hominin specimen, 2.8-2 million years old and attributed to Australopithecus africanus, exhibited a trabecular bone distribution resembling that found in both recent and fossil Homo sapiens, and that is consistent with bipedal hip loading. In contrast, a younger specimen of uncertain taxonomy exhibited a distribution resembling that observed in gorillas, chimpanzees, and orangutans, and that is consistent with regular use of highly flexed hip postures associated with climbing. The results suggest that the A. africanus specimen had a predominantly bipedal, human-like gait, whereas the younger specimen may have regularly engaged in both bipedalism and climbing. According to the authors, the results provide evidence of diverse locomotion among ancient hominins.
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Article #19-14481: "Evidence for habitual climbing in a Pleistocene hominin in South Africa," by Leoni Georgiou et al.
MEDIA CONTACT: Leoni Georgiou, University of Kent, Canterbury, UNITED KINGDOM; tel: +44-7763791935; e-mail: leoni.georgiou@gmail.com
Journal
Proceedings of the National Academy of Sciences