An updated age for the Xujiayao hominin from the Nihewan Basin, North China: Implications for Middle Pleistocene human evolution in East Asia
An updated age for the Xujiayao hominin from the Nihewan Basin, North China: Implications for Middle Pleistocene human evolution in East Asia
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DOI：
10.1016/j.jhevol.2017.01.014
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发表时间：
2017-05-01
影响因子：
3.2
通讯作者：
Xu, Xinwen
中科院分区：
文献类型：
--
作者：
Ao, Hong;Liu, Chun-Ru;Xu, Xinwen
泥河湾盆地徐家窑遗址是东亚地区重要的旧石器时代遗址之一。二十个人属化石，以前被分配到一个古老的智人组，已被挖掘沿着超过30,000石器和类似的5000哺乳动物化石标本。自20世纪70年代徐家窑遗址出土以来，人们一直在对其进行年代测定，但由于应用于现有材料的年代测定技术的局限性，其年代一直存在争议。本文根据沉积物中石英的电子自旋共振（ESR）测年和高分辨率河湖层序的磁性地层学研究，对徐家窑古人类进行了新的年龄测定。磁性地层学研究表明，徐家窑记录了松山上极性时和布鲁赫上极性时。ESR测年结果表明，含Homo层的平均年龄为260-370 ka，这与磁性地层学所指示的中Brunhes正极性年代相一致。这一年龄估计使徐家窑人成为东亚最古老的中更新世人种，具有尼安德特人的特征。这个年龄与早期丹尼索瓦人（尼安德特人的姐妹群体）出现并殖民欧亚大陆东部的时间一致。我们更新的年龄和徐家窑人化石的尼安德特人特征，特别是丹尼索瓦人的臼齿，使徐家窑人可能代表早期丹尼索瓦人。(C)2017作者（S）爱思唯尔有限公司出版
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 similar to 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. (C) 2017 The Author(s). Published by Elsevier Ltd.