UMR 5288 CNRS, Université Toulouse III - Paul Sabatier, France.
Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, CAS, Beijing, China; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, CAS, Nanjing, China.
J Hum Evol. 2018 Mar;116:1-13. doi: 10.1016/j.jhevol.2017.11.002. Epub 2017 Dec 28.
Locality 1, in the Lower Cave of the Zhoukoudian cave complex, China, is one of the most important Middle Pleistocene paleoanthropological and archaeological sites worldwide, with the remains of c. 45 Homo erectus individuals, 98 mammalian taxa, and thousands of lithic tools recovered. Most of the material collected before World War II was lost. However, besides two postcranial elements rediscovered in China in 1951, four human permanent teeth from the 'Dragon Bone Hill,' collected by O. Zdansky between 1921 and 1923, were at the time brought to the Paleontological Institute of Uppsala University, Sweden, where they are still stored. This small sample consists of an upper canine (PMU 25719), an upper third molar (PMU M3550), a lower third premolar crown (PMU M3549), and a lower fourth premolar (PMU M3887). Some researchers have noted the existence of morpho-dimensional differences between the Zhoukoudian and the H. erectus dental assemblage from Sangiran, Java. However, compared to its chrono-geographical distribution, the Early to Middle Pleistocene dental material currently forming the Chinese-Indonesian H. erectus hypodigm is quantitatively meager and still poorly characterized for the extent of its endostructural variation. We used micro-focus X-ray tomography techniques of virtual imaging coupled with geometric morphometrics for comparatively investigating the endostructural conformation (tissue proportions, enamel thickness distribution, enamel-dentine junction morphology, pulp cavity shape) of the four specimens stored in Uppsala, all previously reported for their outer features. The results suggest the existence of time-related differences between continental and insular Southeast Asian dental assemblages, the Middle Pleistocene Chinese teeth apparently retaining an inner signature closer to the likely primitive condition represented by the Early Pleistocene remains from Java, while the Indonesian stock evolved toward tooth structural simplification.
地点 1 位于中国周口店洞穴复合体的下洞穴，是世界上最重要的中更新世古人类学和考古学遗址之一，拥有约 45 名直立人个体、98 种哺乳动物类群和数千件石器工具的遗骸。大部分在第二次世界大战前采集的材料都丢失了。然而，除了 1951 年在中国重新发现的两个后肢骨骼外，1921 年至 1923 年由 O. Zdansky 收集的来自“龙骨山”的四颗人类恒齿，当时被带到瑞典乌普萨拉大学古生物学研究所，至今仍存放在那里。这个小样本由一个上颌犬齿（PMU 25719）、一个上颌第三磨牙（PMU M3550）、一个下颌第三前磨牙冠（PMU M3549）和一个下颌第四前磨牙（PMU M3887）组成。一些研究人员注意到周口店和爪哇 Sangiran 的直立人牙齿组合之间存在形态尺寸差异。然而，与它们的时间地理分布相比，目前构成中国-印度尼西亚直立人雏形的早至中更新世牙齿材料在数量上是微不足道的，其内部结构变化的特征仍然很差。我们使用虚拟成像的微焦点 X 射线断层扫描技术和几何形态计量学来比较研究保存在乌普萨拉的四个标本的内结构构象（组织比例、釉质厚度分布、釉质-牙本质交界处形态、牙髓腔形状），这些标本以前都报告过它们的外部特征。结果表明，大陆和岛屿东南亚牙齿组合之间存在与时间相关的差异，中更新世中国牙齿显然保留了更接近爪哇早更新世遗骸所代表的原始状态的内部特征，而印度尼西亚种群则朝着牙齿结构简化的方向进化。
