生存于中更新世晚期-晚更新世早期的过渡阶段距今13万年左右的马坝人头骨化石,因其圆形的似尼安德特人的眼眶引起学术界的广泛关注,有学者提出马坝人可能是欧洲基因流向亚洲东部的结果.本文利用高分辨率工业CT技术对马坝头骨内部的解剖结构(包括骨壁结构、颅内模、眼窝和额窦)进行了3D复原,以期获得更多的演化上的信息.CT图像显示马坝右侧额骨表面的半圆型凹陷,符合局部受外力打击造成的外伤愈合后所致,体现出当时人类之间面对面的争斗行为.根据3D虚拟复原的颅内模,推算马坝人的颅容量为1300cc左右,位于现代人、尼安德特人和海德堡人的变异范围之中.马坝颅内模表现出似海德堡人和直立人的较窄的额叶、短而扁平的顶叶和前支发达的脑膜中动脉;另外一些特征,如眼窝位于脑的前面、额鳞隆起、额窦较大且占据眶上圆枕的大部分,又与现代人及尼安德特人接近.总体来看,马坝人头骨具有海德堡人、尼安德特人、中国早期古老型人类(直立人)及现代人混合的体质特征.考虑到马坝人的年代早于典型尼安德特人出现的时期,马坝人与尼安德特人可能来自同一祖先,经过多次迁徙和融合最终演化成本地的古老型人类.%The Maba cranium human fossil,dating at 130ka years ago and surviving in the transition stage of late Middle Pleistocene to early Late Pleistocene,had been attracted extensive attention based on its Neanderthal like thick,prominent and projecting supraorbital torus that arches over the circular profile orbit.The hypothesis was suggested that the Maba might be the result of gene flow from Europe to the Eastern Asia.In order to better understand the evolutionary stage of the Maba hominid,a high resolution industrial CT scanner was used to extract its internal anatomy and 3D virtual reconstructions of its bone structure,endocast,eyeball,and frontal sinus were performed.CT images of the bone structure shows that the semicircular depression in the right frontal bone was extensively remodeled.Such remodeling takes years after the insult,indicating long term survival and hence the non-lethal nature of the trauma,reflecting the face to face struggle or interhuman violence in the Maba period.Based on the 3D virtual reconstruction of the endocast,the cranial capacity of the Maba is estimated at around 1300cc,within the ranges of modern humans,Neanderthals and Homo heidelbergensis.The Maba endocast presents narrow frontal lobes,short and flattened parietal areas,and dominated anterior branches of the middle meningeal vessels,as in H.heidelbergensis and H.erectus.The anterior position of eyeball relative to the the frontal lobes,the budged frontal squama,the big frontal sinus which extend to the middle of the supraorbital torus,are similar to Neanderthals and modern humans.Overall,the Maba cranium has mosaic morphological features of H.heidelbergensis,Neanderthals,Chinese archaics and modern humans.Considering the earlier geological dating of the Maba hominid than the typical Neanderthals,alternatively hypothesis is that the Maba and the Neanderthals probably came from the same ancestor,passing through convergence and multiple migration patterns,and evolving into the local archaics.
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