@article{dce22473485748608d9ffba942fef7a1,
title = "New fossils of Australopithecus Sediba reveal a nearly complete lower back",
abstract = "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 ({\textquoteleft}pyramidal configuration{\textquoteright}). These results contrast with some recent work on lordosis in fossil hominins, where MH2 was argued to demonstrate no appreciable lordosis ({\textquoteleft}hypolordosis{\textquoteright}) similar to Neandertals. Our three-dimensional geometric morphometric (3D GM) analyses show that MH2{\textquoteright}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.",
keywords = "Animals, Back/anatomy & histology, Female, Fossils/anatomy & histology, Hominidae/anatomy & histology, Locomotion, Posture",
author = "Williams, {Scott A.} and Prang, {Thomas Cody} and Meyer, {Marc R.} and Nalley, {Thierra K.} and {Van Der Merwe}, Renier and Christopher Yelverton and Daniel Garc{\'i}a-Mart{\'i}nez and Russo, {Gabrielle A.} and Ostrofsky, {Kelly R.} and Jeffrey Spear and Jennifer Eyre and Mark Grabowski and Shahed Nalla and Markus Bastir and Peter Schmid and Churchill, {Steven E.} and Berger, {Lee R.}",
note = "Funding Information: We thank the University of the Witwatersrand and the Evolutionary Studies Institute, as well as the South African National Centre of Excellence in PalaeoSciences and Bernhard Zipfel and Sifelani Jirah for curating the A. sediba material and allowing us access to it and to fossil comparative material in the Phillip V Tobias Fossil Primate and Hominid Laboratory. We are grateful to Kudakwashe Jakata and Kris-tian Carlson for µCT scanning the A. sediba fossils, and Kristian, Morgan Hill, and Erik Mazelis for help processing the µCT scans. We thank the South African Heritage Resource agency for the permits to work at Malapa, and the Nash family for granting access to the site and continued support of research on their reserve, along with the South African Department of Science and Technology, the Gauteng Provincial Government, the Gauteng Department of Agriculture, Conservation and Environment and the Cradle of Humankind Management Authority, the South African National Research Foundation and the African Origins Platform, the National Geographic Society, the Palaeontological Scientific Trust (PAST), and the University of Witwatersrand{\textquoteright}s Schools of Geosciences and Anatomical Sciences and the Bernard Price Institute for Paleontology for support and facilities, as well as our respective universities. We thank the following individuals for curating and providing access to comparative materials in their care: Mirriam Tawane, Stephany Potze, and Lazarus Kgasi (Ditsong National Museum of Natural History); Brendon Billings and Anja Meyer (Dart Collection, University of the Witwatersrand); Yonas Yilma, Tomas Getachew, Jared Assefa, and Getachew Senishaw (National Museum of Ethiopia and Authority for Research and Conservation of Cultural Heritage); Emma Mbua (National Museums of Kenya); V{\'e}ronique Laborde, Liliana Huet, Dominique Grimaud-Herv{\'e}, and Martin Friess (Mus{\'e}e de l{\textquoteright}Homme); Rachel Ives (the Natural History Museum, London); Wim Wendelen and Emmanuel Gilissen (Mus{\'e}e Royal de l{\textquoteright}Afrique Centrale); Lyman Jellema and Yohannes Haile-Selassie (Cleveland Museum of Natural History); and Gisselle Garcia, Ashley Hammond, Eileen Westwig, Eleanor Hoeger, Aja Marcato, Brian O{\textquoteright}Toole, Marisa Surovy, Sarah Ketelsen, and Neil Duncan (American Museum of Natural History). Bill Kimbel and Chris Stringer facilitated access to fossils, and Erik Trinkaus shared high-quality casts of Kebara 2 and Shanidar 3. Publisher Copyright: {\textcopyright} Williams et al.",
year = "2021",
doi = "10.7554/eLife.70447",
language = "English (US)",
volume = "10",
journal = "eLife",
issn = "2050-084X",
publisher = "eLife Sciences Publications",
}