第四纪研究 2002年 Hexian in all of these above mentioned features except the height of the pyramid because of the lack of this part of specimen. Skulls of Hexian and Tangshan are similar in ot having a wide chignon at the occipital region which presented in ZKD skulls. So all of these could ot be the markers dividing the Middle pleistocene population of China into a orthern and a southern one Tangshan skull No. I is different from those of ZkD in possessing more developed marginal process of zygomatic bone, absence of severe constriction around the frontozygomatic suture presence of narrow ridge along the internasal suture, surface bulge between the py riforme orifice and the orbit, ore protruding nasal saddle and much bigger difference between ine breadth of the upper and lower margins of the nasal bone etc. but all of these differences could ot be checked in hexian skull because of the lack of corresponding parts in that specimen. New specimens are needed to investigate more information on the variations of Middle pleistocene Homo erectus in China Comparison between mand:il es fom: ZKD, Chenjiawo and Hexian, and between skulls from ngwangling and Yurxan, and amng teeth from different sites have also been made. All the comparisons show obvious population differences but provide o evidence to divide the pleistocene populations in China into a orthern group and a southern one like the situations in neolithic age and present The protruding nasal saddle of Yunxian skull No. 2 and Tangshan skull No. 1, the surface bulge between the pyriforme orifice and the orbit in the latter specimen as well as the presence of the mid-sagittal prominence in Tangshan skull No. 2 instead of a ridge are extraordinary features in fossil humans of China, but these features could be much ore frequently seen in fossil humans of Africa nd Europe especially in the Neanderthal lineage. The fortuitous occurence of these features in Homo erectus of China indicates the probably small amunts of gene flow between Oriental and West regions of the world in the Pleistocene. In addition, there are many other morphological features of Homo erectus fossils in China shared with Homo sapiens fossils of China such as quadrangular shape the orbit, a nearly oriental curved suture formed with nasofrontal and frontor maxillary sutures mre forward facing of the antero lateral surface of frontor spheoidal process of the zygomatic bone curved lower margin of the bones of cheek region, the presence of a mid sagittal nidge on the frontal bone, shovel-shaped upper incisor etc. The presence of these features in both Homo erectus and Homo sapiens fossil skulls in China supports the continuity in human evolution of China. In sum this preliminary study on the orphological variation of Homo erectus in China supports the hypothesis continuity with hybridization, advocating that continuity marks the main process of human evolution in China in which gene exchange took place subsidiarily. The question whether some of the differences belong to intrapopulation variation or they are actual geographical or chronological differences needs to be investigated. It is especially important to find mre sites and mre fossils in future to make the question approximating a better answer Key words China, Homo erectUs, variation o1994-2006ChinaAcademicJOurnalElectronicPublishingHouse.Allrightsreservedhttp:/www.cHexian in all of these above mentioned features except the height of the pyramid because of the lack of this part of specimen. Skulls of Hexian and Tangshan are similar in not having a wide chignon at the occipital region which presented in ZKD skulls. So all of these could not be the markers dividing the Middle Pleistocene population of China into a northern and a southern one. Tangshan skull No. 1 is different from those of ZKD in possessing more developed marginal process of zygomatic bone , absence of severe constriction around the fronto2zygomatic suture , presence of narrow ridge along the internasal suture , surface bulge between the pyriforme orifice and the orbit , more protruding nasal saddle and much bigger difference between the breadth of the upper and lower margins of the nasal bone etc. But all of these differences could not be checked in Hexian skull because of the lack of corresponding parts in that specimen. New specimens are needed to investigate more information on the variations of Middle Pleistocene Homo erectus in China. Comparison between mandibles from ZKD , Chenjiawo and Hexian , and between skulls from Gongwangling and Yunxian , and among teeth from different sites have also been made. All the comparisons show obvious population differences but provide no evidence to divide the Pleistocene populations in China into a northern group and a southern one like the situations in neolithic age and present day. The protruding nasal saddle of Yunxian skull No. 2 and Tangshan skull No. 1 , the surface bulge between the pyriforme orifice and the orbit in the latter specimen as well as the presence of the mid2sagittal prominence in Tangshan skull No. 2 instead of a ridge are extraordinary features in fossil humans of China , but these features could be much more frequently seen in fossil humans of Africa and Europe especially in the Neanderthal lineage. The fortuitous occurence of these features in Homo erectus of China indicates the probably small amounts of gene flow between Oriental and West regions of the world in the Pleistocene. In addition , there are many other morphological features of Homo erectus fossils in China shared with Homo sapiens fossils of China such as quadrangular shape of the orbit , a nearly horizontal curved suture formed with naso2frontal and fronto2maxillary sutures , more forward facing of the antero2lateral surface of fronto2sphenoidal process of the zygomatic bone , curved lower margin of the bones of cheek region , the presence of a mid2sagittal ridge on the frontal bone , shovel2shaped upper incisor etc. The presence of these features in both Homo erectus and Homo sapiens fossil skulls in China supports the continuity in human evolution of China. In sum , this preliminary study on the morphological variation of Homo erectus in China supports the hypothesis continuity with hybridization , advocating that continuity marks the main process of human evolution in China in which gene exchange took place subsidiarily. The question whether some of the differences belong to intrapopulation variation or they are actual geographical or chronological differences needs to be investigated. It is especially important to find more sites and more fossils in future to make the question approximating a better answer. Key words China , Homo erectus , variation 82 第 四 纪 研 究 2 0 0 2 年