北京房山十渡西太平洞晚更新世哺乳动物化石

北京市房山区十渡镇西太平村发现的动物化石是首次在该镇辖区发现的更新世化石。动物群由6目、15科、22属的22种组成,以岩羊、香麝及鼯鼠等为主,为典型的北方山区动物群。该动物群的时代为晚更新世晚期,~(14)C年代为距今29335～37350年,与山顶洞及田园洞动物群基本同期。西太平洞动物群中有76%的种曾出现于周口店田园洞动物群,而只有38%的种曾出现于山顶洞。目前在此发现的可鉴定到种的化石材料均可归入现生种,但其中有23%的种已经在北京地区消失,消失属种以大中型动物为主。在该地点发现的西伯利亚飞鼠和复齿鼯鼠材料是首次在华北地区发现的此类化石记录。该地点是我国北方地区已报道的第四纪化石点中含香麝和岩羊材料最丰富的地点之一。在国内有关文献中,岩羊化石的分类命名一直没有得到统一,这次发现的新材料,有利于澄清该类化石的分类命名问题。

LATE PLEISTOCENE MAMMALIAN FOSSILS FROM THE XITAIPING CAVE, SHIDU, BEIJING

Xitaiping Cave,a recently found Late Pleistocene locality,is the first recovery of Pleisto- cene mammalian fauna in the Shidu area in the far suburb of Beijing.The locality is located near the Xitaiping Village,20 km north of the Shidu Town (N39°45′02.3″,E115°34′44.5″). The cave occurred in the limestone of Precambrian age.The elevation of the entrance of the cave is 546 m.The fossil locality was recovered in 2005. AMS ~(14)C dating of mammalian bones gave the results:29 335～37 350 yrs BP.In chrono- logy,they are correlated with the Tianyuan Cave and Upper Cave Faunas at Zhoukoudian. More than a thousand pieces of fossils have been collected in Xitaiping Cave.The compo- nents of the fauna are as follows:Erinaceus sp.,Soriculus hypsibius,Rhinolophus ferrumequi- num,Eptesicus serotinus,Murina leucogaster,Lepus sp.,Ochotona sp.,Eutamias sibiricus, Pteromys volans,Aeretes melanopterus,Trogopterus xanthipes,Cricetulus barabensis,Rattus nor- vegicus,Microtus mandarinus,Vulpes vulpes,Arctonyx collaris,Mustela sp.,Mattes sp.,Sus scrofa,Moschus moschiferus,Cervus nippon and Pseudois nayaur.The dominant species are Moschus moschiferus,Pseudois nayaur and Aeretes melanopterus,It's a typical mountain fauna. All the taxa are extant ones.The Xitaiping Cave Fauna shares 76% species with the Late Pleis- tocene Fauna from Tianyuan Cave near Zhoukoudian (Choukoutien),and it also has 38% spe- cies in common with the Upper Cave Fauna at Zhoukoudian.In Xitaiping Cave Fauna,23% of the species have become locally extinct,most of which are medium and large mammals.The differences in compositions of the three contemporary faunas can be attributed to the difference in ecological environment. No reliable evidence of human activity has been detected in the cave,because there is nei- ther cut marks nor gnawing marks left on the bones.The cave deposits are composed of silt- gravel,and the gravels are fairly rounded.It indicates that the deposits were derived from water flows.