| Title |
The age of Homo naledi and associated sediments in the Rising Star Cave, South Africa
|
|---|---|
| Published in |
eLife, May 2017
|
| DOI | 10.7554/elife.24231 |
| Pubmed ID | |
| Authors |
Paul HGM Dirks, Eric M Roberts, Hannah Hilbert-Wolf, Jan D Kramers, John Hawks, Anthony Dosseto, Mathieu Duval, Marina Elliott, Mary Evans, Rainer Grün, John Hellstrom, Andy IR Herries, Renaud Joannes-Boyau, Tebogo V Makhubela, Christa J Placzek, Jessie Robbins, Carl Spandler, Jelle Wiersma, Jon Woodhead, Lee R Berger |
| Abstract |
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 (222)Rn 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. |
Login to access the Attention Digest and the Sentiment Analysis related to this output.
X Demographics
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 21 | 14% |
| Spain | 15 | 10% |
| United Kingdom | 13 | 9% |
| France | 10 | 7% |
| Australia | 8 | 5% |
| South Africa | 8 | 5% |
| Canada | 8 | 5% |
| Sweden | 4 | 3% |
| Netherlands | 3 | 2% |
| Other | 22 | 15% |
| Unknown | 38 | 25% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 108 | 72% |
| Scientists | 32 | 21% |
| Science communicators (journalists, bloggers, editors) | 8 | 5% |
| Practitioners (doctors, other healthcare professionals) | 2 | 1% |
Mendeley readers
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 1 | <1% |
| Mexico | 1 | <1% |
| Ireland | 1 | <1% |
| Canada | 1 | <1% |
| Australia | 1 | <1% |
| Unknown | 311 | 98% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 60 | 19% |
| Student > Bachelor | 54 | 17% |
| Researcher | 36 | 11% |
| Student > Master | 35 | 11% |
| Professor | 20 | 6% |
| Other | 43 | 14% |
| Unknown | 68 | 22% |
| Readers by discipline | Count | As % |
|---|---|---|
| Agricultural and Biological Sciences | 58 | 18% |
| Arts and Humanities | 41 | 13% |
| Social Sciences | 30 | 9% |
| Earth and Planetary Sciences | 28 | 9% |
| Biochemistry, Genetics and Molecular Biology | 23 | 7% |
| Other | 47 | 15% |
| Unknown | 89 | 28% |