摘要
泥河湾盆地最初以其广泛分布的含化石河湖相地层而受关注,并以其丰富的哺乳动物化石而著称于世,而今,泥河湾盆地已成为世界著名旧石器考古重地和研究第四纪地质古生物的重要场所。狭义泥河湾动物群(或下沙沟动物群)是我国北方早更新世的标准动物群,其古地磁年龄是2.2-1.7 MaBP。随着地层古生物工作的深入开展,盆地内也发现了若干中-晚更新世化石点;丁家堡水库全新统中发现的象颊齿,之前被鉴定为亚洲象,新的测年数据表明其时代大于5万年,依据牙齿测量数据和形态特征,本研究将其归入诺氏古菱齿象。目前已在泥河湾盆地发现百余个化石地点,鉴定出236种(包括未定属种)哺乳动物,分属于8目、32科和121属,其中38个属种(包括亚种)最初是以泥河湾化石材料而建立。总而言之,泥河湾盆地哺乳动物化石以早更新世者居多,并且化石材料保存完好;有些属种在欧亚大陆古北区第四纪哺乳动物群形成过程中发挥过重要作用,例如早期猛犸象、披毛犀、野牛及真枝角鹿等,还有直隶狼、貉及各种真马。泥河湾盆地由于河流和断层切割以及沉积相变等原因,导致各个化石点及史前考古遗址地层难以直接对比,更难全窥盆地内动物群演化的整体脉络;新的生物地层对比研究表明,桑干河南岸的岑家湾台地周缘的早更新世化石点,其主化石层位与下沙沟地区经典泥河湾动物群的层位大致相当。泥河湾盆地哺乳动物化石主要产自细砂、粉砂及黏土地层;化石成堆产出或者呈条带状及凸镜状分布的特点,多数与水流搬运有关。除过1枚豪猪牙齿和少量麂类化石之外,泥河湾盆地第四纪哺乳动物群中几乎不含东洋界动物,总体反映了干冷草原为主的古环境背景。
The Nihewan(Nihowan)Basin attracted researcher’s attention by its rich fluviolacustrine deposits initially and then by its diversified mammalian fossils.Currently it is a hot spot for Paleolithic archaeology,Quaternary geology and for paleontology.The Nihewan fauna sensu stricto has been regarded as the type fauna for the Early Pleistocene Epoch in North China,whose paleomagnetic age is 2.2-1.7 MaBP.Whereas the further stratigraphical investigations inside the Basin have also resulted in discoveries of mammalian faunas of Mid-Late Pleistocene epochs.Elephant remains recovered in Holocene deposits at Dingjiabu reservoir were identified as Elephas maximus by a previous study,while recent dating work shows the actual age of these remains as older than 50 kaBP,with a morphological study of these fossils indicating an inclusion into the species Palaeoloxodon naumanni.Up to now,more than 100 fossil localities have been discovered in the Nihewan Basin,and approximately 236 mammal species have been recognized that belong to 8 orders,32 families,and 121 genera.Around 38 species(including subspecies)were originally established based on well preserved and diversaified fossil materials from here.Some of the taxa with important roles in forming the initial Paleoarctic fauna are early mammoth(Mammuthus meridionalis and M.trogontherii),woolly rhino(Coelodonta nihowanensis),early bison(Bison palaeosinensis)and comb-antlered deer(Eucladoceros boulei),Chihli wolf(Canis chihliensis),raccoon dogs(Nyctereutes spp.)and diverse horses(Equus spp.).Because of the cut of rivers and faults as well as the facies changes,chronological correlations among different sites in the Nihewan Basin is not easy,which makes it difficult to get a general view of evolutionary patterns of fauna.The present study shows Early Pleistocene fossil sites around the Cenjiawan(Cheng-chia-wan)platform at the southern bank of the Sangganhe(Sangkanho)River should share similar geologic ages as the type locality of Nihewan fauna sensu stricto at Xiashagou on the northern bank of the river.Fossiliferous strata in the Nihewan Basin are mainly limited to sand,silt and clay layers.Bones usually form lenticular masses or appear in piles along trenches in situ,which should be the result from transportation by water.Except for one tooth of Hystrix and a few fossils of muntjac,the Pleistocene mammalian fauna in the Nihewan Basin is exclusively composed of Paleoarctic animals,which indicates a cool steppe dominated environment.
作者
同号文
张贝
陈曦
TONG Haowen;ZHANG Bei;CHEN Xi(Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences,Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044;University of Chinese Academy of Sciences,Beijing 100049;National Natural History Museum of China,Beijing 100050;Nanjing Normal University,Nanjing 210023)
出处
《人类学学报》
CSCD
北大核心
2024年第1期157-183,共27页
Acta Anthropologica Sinica
基金
国家重点研发计划(2020YFC1521500)
国家自然科学基金(42172021,41572003)
科技基础资源调查专项资助(2023YF100905)