Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.
CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China.
Sci Adv. 2019 Jan 16;5(1):eaau0930. doi: 10.1126/sciadv.aau0930. eCollection 2019 Jan.
Several human dental traits typical of modern humans appear to be associated with the prolonged period of development that is a key human attribute. Understanding when, and in which early hominins, these dental traits first appeared is thus of strong interest. Using x-ray multiresolution synchrotron phase-contrast microtomography, we quantify dental growth and development in an archaic juvenile from the Xujiayao site in northern China dating to 161,000-224,000 years or 104,000-125,000 years before present. Despite the archaic morphology of Xujiayao hominins, most aspects of dental development of this juvenile fall within modern human ranges (e.g., prolonged crown formation time and delayed first molar eruption). For its estimated age-at-death (6.5 years), its state of dental development is comparable to that of equivalently aged modern children. These findings suggest that several facets of modern human dental growth and development evolved in East Asia before the appearance of fully modern human morphology.
几项典型的现代人牙齿特征似乎与人类的长期发育有关，这是人类的一个关键特征。因此，了解这些牙齿特征最早出现在何时以及哪些早期人类身上具有重要意义。利用 X 射线多分辨率同步加速器相衬微断层扫描技术，我们对来自中国北方徐家窑遗址的 16.1 万至 22.4 万年前或 10.4 万至 12.5 万年前的一个古老的未成年个体的牙齿生长和发育进行了定量分析。尽管徐家窑人类具有古老的形态，但该未成年个体的大多数牙齿发育方面都在现代人范围内（例如，冠形成时间延长，第一磨牙萌出延迟）。就其估计的死亡年龄（6.5 岁）而言，其牙齿发育状况与同龄现代儿童相当。这些发现表明，几个方面的现代人牙齿生长和发育在完全具有现代人形态之前就在东亚进化。
