The age of and associated sediments in the Rising Star Cave, South Africa.

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 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 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 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 fossils, we have constrained the depositional age of to a period between 236 ka and 335 ka. These age results demonstrate that a morphologically primitive hominin, survived into the later parts of the Pleistocene in Africa, and indicate a much younger age for the fossils than have previously been hypothesized based on their morphology.