New fossils of Australopithecus sediba reveal a nearly complete lower back
Autor: | Renier Van Der Merwe, Mark Grabowski, Thomas C. Prang, Jeffrey Spear, Peter Schmid, Jennifer Eyre, Scott A. Williams, Gabrielle A. Russo, Kelly R. Ostrofsky, Thierra K. Nalley, Steven E. Churchill, Christopher Yelverton, Shahed Nalla, Lee R. Berger, Marc R. Meyer, Daniel García-Martínez, Markus Bastir |
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Přispěvatelé: | Leakey Foundation, Agencia Estatal de Investigación (España), CSIC - Museo Nacional de Ciencias Naturales (MNCN) |
Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
vertebral column
QH301-705.5 Science upright posture lordosis General Biochemistry Genetics and Molecular Biology QH301 human evolution Cave Human spine Bipedalism Biology (General) Australopithecus sediba geography geography.geographical_feature_category General Immunology and Microbiology Adult female biology General Neuroscience bipedalism social sciences General Medicine Antropología biológica biology.organism_classification Genealogy Evolución Human evolution Climbing Paleoanthropology paleoanthropology Medicine human activities |
Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname eLife, Vol 10 (2021) E-Prints Complutense. Archivo Institucional de la UCM |
ISSN: | 2050-084X |
Popis: | Adaptations of the lower back to bipedalism are frequently discussed but infrequently demonstrated in early fossil hominins. Newly discovered lumbar vertebrae contribute to a near-complete lower back of Malapa Hominin 2 (MH2), offering additional insights into posture and locomotion in Australopithecus sediba. We show that MH2 possessed a lower back consistent with lumbar lordosis and other adaptations to bipedalism, including an increase in the width of intervertebral articular facets from the upper to lower lumbar column (‘pyramidal configuration’). These results contrast with some recent work on lordosis in fossil hominins, where MH2 was argued to demonstrate no appreciable lordosis (‘hypolordosis’) similar to Neandertals. Our three-dimensional geometric morphometric (3D GM) analyses show that MH2’s nearly complete middle lumbar vertebra is human-like in overall shape but its vertebral body is somewhat intermediate in shape between modern humans and great apes. Additionally, it bears long, cranially and ventrally oriented costal (transverse) processes, implying powerful trunk musculature. We interpret this combination of features to indicate that A. sediba used its lower back in both bipedal and arboreal positional behaviors, as previously suggested based on multiple lines of evidence from other parts of the skeleton and reconstructed paleobiology of A. sediba. Funding: Leakey Foundation, Scott A Williams; Agencia Estatal de Investigación (Museo Nacional de Ciencias Naturales CSIC PID2020-115854GB-I00), Markus Bastir. |
Databáze: | OpenAIRE |
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