Acta Anthropologica Sinica ›› 2021, Vol. 40 ›› Issue (05): 739-750.doi: 10.16359/j.cnki.cn11-1963/q.2020.0015

• Research Articles •     Next Articles

The incisive canal position of the Chinese Pleistocene humans and its evolutionary implications

LIU Wu1,2(), HUI Jiaming1,2, HE Jianing3, WU Xiujie1,2   

  1. 1. Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044
    2. CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044
    3. Peking University, Beijing 100083
  • Received:2020-02-08 Revised:2020-04-10 Online:2021-10-15 Published:2021-10-15

Abstract:

When studying the fossils of Homo erectus from Zhoukoudian, Weidenreich pointed out that the incisive foramen is more posteriorly positioned compared with that of modern humans in which the foramen is situated anteriorly more close to alveolar border. Since then, incisive foramen have been used in paleoanthroology studies as an indicator with evolutionary value. However, till now, only one Chinese human fossil from Zhoukoudian was studied for the position of incisive foramen while no study of incisive foramen positions in modern Chinese has been conducted. In this study, the positions of incisive foramen of Chinese human fossils and specimens of modern Chinese population were observed and measured. Based on these, in conjunction with previous studies of incisive foramen of human fossils around the world, the expression pattern and evolutionary implications of the incisive foramen positions for Chinese human fossils were explored. Our study indicates that from Early Pleistocene to Late Pleistocene, the positions of incisive foramens in Chinese human fossils follow the trend to the anterior positions. The positions of incisive foramens in Early and Middle Pleistocene Homo erectus (Yunxian and Zhoukoudian) are more posteriorly positioned; In late Middle Pleistocene, the positions of incisive foramens in some specimens (Dali, Changyang, Hualongdong) are moved forwardly resembling those of modern humans, while other specimens (Jinniushan, Chaoxian) exhibit posteriorly positioned incisive foramens, which are within the variation ranges of Homo erectus; In all the specimens of Late Pleistocene humans, the positions of incisive foramens situate anteriorly within the variation ranges of modern humans. The investigation of the incisive foramen in modern Chinese population show that although the positions in modern humans are anterior, the size and shape of the incisive foramens in modern humans exhibit pronounced variabilities. This expression pattern of the incisive foramens in modern humans will affect the evaluations to the position and evolutionary implications of the incisive foramens. In additions, nearly all the incisive foramens in modern human specimens are open in their anterior borders and the incisive canals take inclined trends towards superoposterior directions from the entrance. This discovery is different from the vertical direction of the incisive canals in modern humans proposed by Weidenreich. In considering the investigated data of the incisive foramens in Chinese human fossils, modern Chinese specimens and incisive foramen positions of other human fossils around the world, the authors believe that the positions of incisive foramens exhibit relatively fixed pattern in the human evolution and posteriorly positioned incisive foramens should be treated as a primitive traits.

Key words: Incisive canal, Fossil humans in China, Modern humans, Human evolution

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