TY - JOUR
T1 - Human-like hip joint loading in Australopithecus africanus and Paranthropus robustus
AU - Ryan, Timothy M.
AU - Carlson, Kristian J.
AU - Gordon, Adam D.
AU - Jablonski, Nina
AU - Shaw, Colin N.
AU - Stock, Jay T.
N1 - Funding Information:
We thank curators and collections managers at the following institutions: American Museum of Natural History; Smithsonian National Museum of Natural History; Illinois State Museum; Center for Archaeological Investigations, Southern Illinois University Carbondale; the Cambridge Archaeological Unit and Duckworth Museum, Cambridge University, for access to skeletal material in their care. We also thank Antoine Balzeau at the Muséum National d’Histoire Naturelle AST-RX, Paris for access to fossil specimens and μCT scanning services. We thank both the Evolutionary Studies Institute (ESI) at the University of the Witwatersrand (Wits), particularly the Fossil Access Committee, and the Ditsong National Museum of Natural History for allowing us to collect high-resolution image data from fossils in their collections. We thank Dr. Bernhard Zipfel and Sifelani Jirah for facilitating access to fossils curated in the Wits hominin fossil collection. We also thank Stephany Potze formerly at the Ditsong National Museum of Natural History for facilitating access to fossils curated in their collection. We thank the Microfocus X-ray Computed Tomography facility in the ESI for allowing us to use its facilities in collecting the high-resolution image data. Finally, we thank the National Research Foundation (South Africa) and the Department of Science and Technology (South Africa) for funding provided to the scanning facilities and the Virtual Imaging in Paleontology (VIP) lab where initial image processing took place. This research was supported by National Science Foundation Grant BCS-0617097 (to T.M.R.), the South Africa National Research Foundation and Department of Science and Technology (to K.J.C.), and the European Research Council under the European Union's Seventh Framework Programme (FP/2007–2013)/ERC Grant Agreement no. 617627 (to J.T.S.).
Funding Information:
We thank curators and collections managers at the following institutions: American Museum of Natural History; Smithsonian National Museum of Natural History; Illinois State Museum; Center for Archaeological Investigations, Southern Illinois University Carbondale; the Cambridge Archaeological Unit and Duckworth Museum, Cambridge University, for access to skeletal material in their care. We also thank Antoine Balzeau at the Mus?um National d'Histoire Naturelle AST-RX, Paris for access to fossil specimens and ?CT scanning services. We thank both the Evolutionary Studies Institute (ESI) at the University of the Witwatersrand (Wits), particularly the Fossil Access Committee, and the Ditsong National Museum of Natural History for allowing us to collect high-resolution image data from fossils in their collections. We thank Dr. Bernhard Zipfel and Sifelani Jirah for facilitating access to fossils curated in the Wits hominin fossil collection. We also thank Stephany Potze formerly at the Ditsong National Museum of Natural History for facilitating access to fossils curated in their collection. We thank the Microfocus X-ray Computed Tomography facility in the ESI for allowing us to use its facilities in collecting the high-resolution image data. Finally, we thank the National Research Foundation (South Africa) and the Department of Science and Technology (South Africa) for funding provided to the scanning facilities and the Virtual Imaging in Paleontology (VIP) lab where initial image processing took place. This research was supported by National Science Foundation Grant BCS-0617097 (to T.M.R.), the South Africa National Research Foundation and Department of Science and Technology (to K.J.C.), and the European Research Council under the European Union's Seventh Framework Programme (FP/2007?2013)/ERC Grant Agreement no. 617627 (to J.T.S.).
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/8
Y1 - 2018/8
N2 - Adaptations indicative of habitual bipedalism are present in the earliest recognized hominins. However, debate persists about various aspects of bipedal locomotor behavior in fossil hominins, including the nature of gait kinematics, locomotor variability across different species, and the degree to which various australopith species engaged in arboreal behaviors. In this study, we analyze variation in trabecular bone structure of the femoral head using a sample of modern humans, extant non-human hominoids, baboons, and fossil hominins attributed to Australopithecus africanus, Paranthropus robustus, and the genus Homo. We use μCT data to characterize the fabric anisotropy, material orientation, and bone volume fraction of trabecular bone to reconstruct hip joint loading conditions in these fossil hominins. Femoral head trabecular bone fabric structure in australopiths is more similar to that of modern humans and Pleistocene Homo than extant apes, indicating that these australopith individuals walked with human-like hip kinematics, including a more limited range of habitual hip joint postures (e.g., a more extended hip) during bipedalism. Our results also indicate that australopiths have robust femoral head trabecular bone, suggesting overall increased loading of the musculoskeletal system comparable to that imposed by extant apes. These results provide new evidence of human-like bipedal locomotion in Pliocene hominins, even while other aspects of their musculoskeletal systems retain ape-like characteristics.
AB - Adaptations indicative of habitual bipedalism are present in the earliest recognized hominins. However, debate persists about various aspects of bipedal locomotor behavior in fossil hominins, including the nature of gait kinematics, locomotor variability across different species, and the degree to which various australopith species engaged in arboreal behaviors. In this study, we analyze variation in trabecular bone structure of the femoral head using a sample of modern humans, extant non-human hominoids, baboons, and fossil hominins attributed to Australopithecus africanus, Paranthropus robustus, and the genus Homo. We use μCT data to characterize the fabric anisotropy, material orientation, and bone volume fraction of trabecular bone to reconstruct hip joint loading conditions in these fossil hominins. Femoral head trabecular bone fabric structure in australopiths is more similar to that of modern humans and Pleistocene Homo than extant apes, indicating that these australopith individuals walked with human-like hip kinematics, including a more limited range of habitual hip joint postures (e.g., a more extended hip) during bipedalism. Our results also indicate that australopiths have robust femoral head trabecular bone, suggesting overall increased loading of the musculoskeletal system comparable to that imposed by extant apes. These results provide new evidence of human-like bipedal locomotion in Pliocene hominins, even while other aspects of their musculoskeletal systems retain ape-like characteristics.
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U2 - 10.1016/j.jhevol.2018.03.008
DO - 10.1016/j.jhevol.2018.03.008
M3 - Article
C2 - 29706230
AN - SCOPUS:85046167346
VL - 121
SP - 12
EP - 24
JO - Journal of Human Evolution
JF - Journal of Human Evolution
SN - 0047-2484
ER -