Department of Geoscience, James Cook University, Townsville, Australia; Evolutionary Studies Institute and the National Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Wits, South Africa
Eric M Roberts
Department of Geoscience, James Cook University, Townsville, Australia; Evolutionary Studies Institute and the National Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Wits, South Africa
Hannah Hilbert-Wolf
Department of Geoscience, James Cook University, Townsville, Australia
Jan D Kramers
Department of Geology, University of Johannesburg, Johannesburg, South Africa
John Hawks
Evolutionary Studies Institute and the National Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Wits, South Africa; Department of Anthropology, University of Wisconsin-Madison, Madison, United States
Anthony Dosseto
School of Earth and Environmental Sciences, University of Wollongong, Wollongong, Australia
Mathieu Duval
Australian Research Centre for Human Evolution, Environmental Futures Research Institute, Griffith University, Nathan, Australia; Geochronology, Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
Marina Elliott
Evolutionary Studies Institute and the National Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Wits, South Africa
Mary Evans
School of Geosciences, University of the Witwatersrand, Wits, South Africa
Rainer Grün
Australian Research Centre for Human Evolution, Environmental Futures Research Institute, Griffith University, Nathan, Australia; Research School of Earth Sciences, The Australian National University, Canberra, Australia
John Hellstrom
School of Earth Sciences, The University of Melbourne, Parkville, Australia
Andy IR Herries
The Australian Archaeomagnetism Laboratory, Department of Archaeology and History, La Trobe University, Melbourne, Australia
New ages for flowstone, sediments and fossil bones from the Dinaledi Chamber are presented. We combined optically stimulated luminescence dating of sediments with U-Th and palaeomagnetic analyses of flowstones to establish that all sediments containing Homo naledi fossils can be allocated to a single stratigraphic entity (sub-unit 3b), interpreted to be deposited between 236 ka and 414 ka. This result has been confirmed independently by dating three H. naledi teeth with combined U-series and electron spin resonance (US-ESR) dating. Two dating scenarios for the fossils were tested by varying the assumed levels of 222Rn loss in the encasing sediments: a maximum age scenario provides an average age for the two least altered fossil teeth of 253 +82/–70 ka, whilst a minimum age scenario yields an average age of 200 +70/–61 ka. We consider the maximum age scenario to more closely reflect conditions in the cave, and therefore, the true age of the fossils. By combining the US-ESR maximum age estimate obtained from the teeth, with the U-Th age for the oldest flowstone overlying Homo naledi fossils, we have constrained the depositional age of Homo naledi to a period between 236 ka and 335 ka. These age results demonstrate that a morphologically primitive hominin, Homo naledi, survived into the later parts of the Pleistocene in Africa, and indicate a much younger age for the Homo naledi fossils than have previously been hypothesized based on their morphology.
