Ao Hong, Liu Chun-Ru, Roberts Andrew P, Zhang Peng, Xu Xinwen
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA.
State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China.
J Hum Evol. 2017 May;106:54-65. doi: 10.1016/j.jhevol.2017.01.014. Epub 2017 Mar 17.
The Xujiayao site in the Nihewan Basin (North China) is one of the most important Paleolithic sites in East Asia. Twenty Homo fossils, which were previously assigned to an archaic Homo sapiens group, have been excavated along with more than 30,000 lithic artifacts and ∼5000 mammalian fossil specimens. Dating of the Xujiayao hominin has been pursued since its excavation in the 1970s, but its age has remained controversial because of limitations of the dating techniques that have been applied to available materials. Here, we report new ages for the Xujiayao hominin based on combined electron spin resonance (ESR) dating of quartz in the sediments and high-resolution magnetostratigraphy of the fluvio-lacustrine sequence. The magnetostratigraphy suggests that the upper Matuyama and Brunhes polarity chrons are recorded at Xujiayao. The ESR dating results indicate a pooled average age of 260-370 ka for the Homo-bearing layer, which is consistent with its position within the middle Brunhes normal polarity chron indicated by magnetostratigraphy. This age estimate makes the Xujiayao hominin among the oldest mid-Pleistocene hominins with derived Neanderthal traits in East Asia. This age is consistent with the time when early Denisovans, a sister group of Neanderthals, appeared and colonized eastern Eurasia. Our updated age and the Neanderthal-like traits of the Xujiayao Homo fossils, particularly the Denisovan-like molar teeth, make it possible that the Xujiayao hominin could represent an early Denisovan.
泥河湾盆地（中国北方）的许家窑遗址是东亚最重要的旧石器时代遗址之一。此前被归为古老型智人群体的20件人类化石，与3万多件石器制品和约5000件哺乳动物化石标本一同被发掘出来。自20世纪70年代许家窑古人类化石被发掘以来，人们一直在对其进行年代测定，但由于应用于现有材料的测年技术存在局限性，其年代一直存在争议。在此，我们基于沉积物中石英的电子自旋共振（ESR）测年与河湖相层序的高分辨率磁性地层学相结合的方法，报告了许家窑古人类的新年代。磁性地层学表明，许家窑记录了松山上部和布容极性时。ESR测年结果显示，含人类化石层的汇总平均年龄为26万至37万年，这与其在磁性地层学所显示的布容正向极性时中期的位置一致。这一年代估计使许家窑古人类成为东亚具有尼安德特人衍生特征的最古老的中更新世古人类之一。这个年代与尼安德特人的姐妹群体——早期丹尼索瓦人出现并殖民欧亚大陆东部的时间一致。我们更新后的年代以及许家窑人类化石的类尼安德特人特征，特别是类似丹尼索瓦人的臼齿，使得许家窑古人类有可能代表早期丹尼索瓦人。
