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Published Online March 4 2015
< Science Express Index

Science DOI: 10.1126/science.aaa1415
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PALEOANTHROPOLOGY

Late Pliocene fossiliferous sedimentary record and the environmental context of early Homo from Afar, Ethiopia

  1. J. Ramón Arrowsmith9
  1. 1Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA.
  2. 2Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287, USA.
  3. 3CNRS Géosciences Rennes, Campus de Beaulieu, 35042 Rennes, France.
  4. 4Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709, USA.
  5. 5Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, 10115 Berlin, Germany.
  6. 6Biology Program, The Richard Stockton College of New Jersey, 101 Vera King Farris Drive, Galloway, NJ 08205, USA.
  7. 7Human Evolution Research Center, University of California, Berkeley, 3101 Valley Life Sciences Building, Berkeley, CA, 94720-3160, USA.
  8. 8Swedish Museum of Natural History, Department of Palaeobiology, Box 50007, SE-10405 Stockholm, Sweden.
  9. 9School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA.
  1. ↵*Corresponding author. E-mail: dimaggio{at}psu.edu (E.N.D.); kreed{at}asu.edu (K.E.R.)

  • ↵† Present address: Institute of Earth and Environmental Science, Potsdam University, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam-Golm, Germany.

Abstract

Sedimentary basins in eastern Africa preserve a record of continental rifting and contain important fossil assemblages for interpreting hominin evolution. However, the record of hominin evolution between 3 and 2.5 million years ago (Ma) is poorly documented in surface outcrops, particularly in Afar, Ethiopia. Here we present the discovery of 2.84-2.58 Ma fossil and hominin-bearing sediments in the Ledi-Geraru research area that have produced the earliest record of the genus Homo. Vertebrate fossils record a faunal turnover indicative of more open and probable arid habitats than those reconstructed earlier in this region, in broad agreement with hypotheses addressing the role of environmental forcing in hominin evolution at this time. Geological analyses constrain depositional and structural models of the Afar and date the LD 350-1 Homo mandible to 2.80-2.75 Ma.

  • Received for publication 23 October 2014.
  • Accepted for publication 13 February 2015.