Abstract

Functional morphology of the atlas reflects multiple aspects of an organism’s biology. More specifically, its shape indicates patterns of head mobility, while the size of its vascular foramina reflects blood flow to the brain. Anatomy and function of the early hominin atlas, and thus, its evolutionary history, are poorly documented because of a paucity of fossilized material. Meticulous excavation, cleaning and high-resolution micro-CT scanning of the StW 573 (‘Little Foot’) skull has revealed the most complete early hominin atlas yet found, having been cemented by breccia in its displaced and flipped over position on the cranial base anterolateral to the foramen magnum. Description and landmark-free morphometric analyses of the StW 573 atlas, along with other less complete hominin atlases from Sterkfontein (StW 679) and Hadar (AL 333-83), confirm the presence of an arboreal component in the positional repertoire of Australopithecus. Finally, assessment of the cross-sectional areas of the transverse foramina of the atlas and the left carotid canal in StW 573 further suggests there may have been lower metabolic costs for cerebral tissues in this hominin than have been attributed to extant humans and may support the idea that blood perfusion of these tissues increased over the course of hominin evolution.

Details

Title
The atlas of StW 573 and the late emergence of human-like head mobility and brain metabolism
Author
Beaudet Amélie 1 ; Clarke, Ronald J 2 ; Heaton, Jason L 3   VIAFID ORCID Logo  ; Pickering, Travis R 4 ; Carlson, Kristian J 5   VIAFID ORCID Logo  ; Crompton, Robin H 6 ; Jashashvili Tea 7 ; Bruxelles Laurent 8   VIAFID ORCID Logo  ; Jakata Kudakwashe 2 ; Bam Lunga 9 ; Luc, Van Hoorebeke 10 ; Kuman Kathleen 11 ; Stratford, Dominic 11   VIAFID ORCID Logo 

1  School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135); Department of Anatomy, University of Pretoria, PO Box 2034, Pretoria, South Africa (GRID:grid.49697.35) (ISNI:0000 0001 2107 2298) 
2  Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135) 
3  Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135); Department of Biology, Birmingham-Southern College, 900 Arkadelphia Road, Birmingham, United States (GRID:grid.253109.c); Plio-Pleistocene Palaeontology Section, Department of Vertebrates, Ditsong National Museum of Natural History (Transvaal Museum), 432 Paul Kruger Street, Pretoria Central, Pretoria, South Africa (GRID:grid.253109.c) 
4  Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135); Department of Biology, Birmingham-Southern College, 900 Arkadelphia Road, Birmingham, United States (GRID:grid.253109.c); Department of Anthropology, University of Wisconsin, Madison, United States (GRID:grid.14003.36) (ISNI:0000 0001 2167 3675) 
5  Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135); Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, 1975 Zonal Avenue, Los Angeles, United States (GRID:grid.42505.36) (ISNI:0000 0001 2156 6853) 
6  Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135); Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, William Henry Duncan Building, W Derby Street, Liverpool, United Kingdom (GRID:grid.10025.36) (ISNI:0000 0004 1936 8470) 
7  Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135); Molecular Imaging Center, Department of Radiology, Keck School of Medicine, University of Southern California, 2250 Alcazar Street, Los Angeles, CA, United States (GRID:grid.42505.36) (ISNI:0000 0001 2156 6853); Department of Geology and Paleontology, Georgian National Museum, 3 Shota Rustaveli Ave, T’bilisi, Georgia (GRID:grid.452450.2) (ISNI:0000 0001 0739 408X) 
8  School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135); French National Institute for Preventive Archaeological Researches (INRAP), 561 rue Etienne Lenoir, Nîmes, France (GRID:grid.11951.3d); French Institute of South Africa (IFAS), USR 3336 CNRS, 62 Juta Street, Braamfontein, Johannesburg, South Africa (GRID:grid.11951.3d) 
9  South African Nuclear Energy Corporation SOC Ltd. (Necsa), Elias Motsoaledi Street Ext. (Church Street West), Pelindaba, South Africa (GRID:grid.11951.3d) 
10  UGCT Department of Physics and Astronomy, Ghent University, Proeftuinstraat 86/N12, Gent, Belgium (GRID:grid.5342.0) (ISNI:0000 0001 2069 7798) 
11  School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa (GRID:grid.11951.3d) (ISNI:0000 0004 1937 1135) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41598-020-60837-2
ProQuest document ID
2377672827
Copyright
This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.