Zhang Yameng, Li Zhanyang
Joint International Research Laboratory of Environmental and Social Archaeology, Shandong University, Qingdao, 266237, China; Institute of Cultural Heritage, Shandong University, Qingdao, 266237, China.
Joint International Research Laboratory of Environmental and Social Archaeology, Shandong University, Qingdao, 266237, China; Institute of Cultural Heritage, Shandong University, Qingdao, 266237, China; Henan Provincial Institute of Cultural Relics and Archaeology, Zhengzhou, 450000, China.
J Hum Evol. 2023 May;178:103347. doi: 10.1016/j.jhevol.2023.103347. Epub 2023 Mar 24.
Results of traditional metric and nonmetric assessments suggest that the Xuchang hominin shares features with Neanderthals. To comprehensively compare the nuchal morphology of XC 2 to those of the genus Homo, we conduct a three-dimensional geometric morphometric study with 35 cranial landmarks and surface semilandmarks of XC 2, Homo erectus, Middle Pleistocene humans, Neanderthals, and early and recent modern humans. Results reveal that the centroid size of XC 2 is larger than that of early and recent modern humans and can only be compared to that of Middle Pleistocene humans and H. erectus. Early and recent modern humans share a nuchal morphology distinct from archaic hominins (Ngandong H. erectus, Middle Pleistocene humans, and Neanderthals), except for SM 3, Sangiran 17, and Asian and African H. erectus. Although Ngandong specimens differ from the other H. erectus, it is unclear whether this represents a temporal or spatial trend in the process of evolution of this species. The nuchal morphological resemblance between Middle Pleistocene humans and Neanderthals may be attributed to similar cranial architecture and cerebellar shape. The great nuchal morphological variation shared by recent modern humans may indicate a particular developmental pattern. In conclusion, the nuchal morphology of different human groups is highly variable and may be caused by different factors including brain globularization and developmental plasticity. XC 2 shares similar nuchal morphology with Middle Pleistocene humans and Neanderthals, but these results are insufficient to fully resolve the taxonomic status of XC 2.
传统的测量和非测量评估结果表明，许昌古人类与尼安德特人有共同特征。为了全面比较许昌2号头骨（XC 2）与智人属其他成员的项部形态，我们对XC 2、直立人、中更新世人类、尼安德特人以及早期和现代人类进行了三维几何形态测量研究，共设置了35个颅骨地标点和表面半地标点。结果显示，XC 2的质心大小大于早期和现代人类，仅可与中更新世人类和直立人的质心大小相比较。除了三吉岭17号头骨（SM 3）、桑吉兰17号头骨以及亚洲和非洲的直立人外，早期和现代人类具有与古老型人类（爪哇直立人、中更新世人类和尼安德特人）不同的项部形态。尽管爪哇标本与其他直立人不同，但尚不清楚这是否代表了该物种进化过程中的时间或空间趋势。中更新世人类和尼安德特人在项部形态上的相似性可能归因于相似的颅骨结构和小脑形状。现代人类之间巨大的项部形态差异可能表明存在一种特殊的发育模式。总之，不同人类群体的项部形态高度可变，可能由包括脑球化和发育可塑性在内的不同因素引起。XC 2与中更新世人类和尼安德特人具有相似的项部形态，但这些结果不足以完全确定XC 2的分类地位。
