秦皇岛山羊寨第2地点中更新世动物群中的仓鼠化石

发布时间：2018-10-22 14:41

【摘要】：山羊寨化石点位于河北秦皇岛市海港区山羊寨村—石灰岩采石场内。到目前为止,先后在该采石场发现了4个独立的化石点,按从南到北的顺序,本文依次将其命名为山羊寨第1、2、3、4地点。其中,第2地点是含化石最丰富的一个地点,在中国北方同期(中更新世晚期或晚更新世)动物群中其化石丰富程度也属罕见。截至目前,在该地点发现的哺乳动物总数已有55种,其中小哺乳动物占46种,一些小哺乳动物的材料经常有成百上千件之多。本文主要研究采集自这一地点的丰富的仓鼠材料。具体研究成果包括:1、综合前人从动物群对比及绝对年龄测定等方面推测的动物群的年代,及最近利用ESR(电子自选共振)法测得的绝对年龄,认为山羊寨第2地点动物群的时代位于中更新世晚期或晚更新世,且更倾向于前者。2、系统研究了动物群中的仓鼠材料共计1625件,同时为对比化石材料观察了现生仓鼠亚科物种标本共200余件。①从化石材料中识别出2属3种仓鼠动物,即大仓鼠属Tscherskia中的大仓鼠T.triton,仓鼠属Cricetulus中的长尾仓鼠C.longicaudatus和黑线仓鼠C.barabensis,三者均为现生种。②从臼齿大小、形状和构造三个方面详细对比了绝灭种变异仓鼠Cricetinusvarians和T.trion的异同,结果表明在上述三个方面两个种的差别均很小,由此认为C.varians应作为T.triton的晚出同物异名而被废弃。且由于C.varians为似仓鼠属 Cricetinus的属型种,因此认为Cricetinus也应作为Tscherskia的晚出同物异名而被废弃,原归于 Cricetinus的除C.的除C.varians外的其余 6 个种(C.europaeus,C.gritzai,C.beremendensis,C.janossyi,C.koufo.si,C.mesolophidu.s)也应全部转置于Tscher-skia内,同时给出了Tscherski了的属征。根据Tscher.skia属各物种的分布特点及首次出现时间,初步认为其有可能在早上新世起源于欧洲,然后扩散至亚洲。③通过对第2地点标本的观察认为,前人提出的两种小型仓鼠ml下前边尖的形态及与其后方下前小脊连接方式的3种类型可能只是仓鼠个体年龄大小的反映,并不具有分类学方面的意义。通过对Clongicaudatu.和C.barabensis现生标本的观察并总结前人成果,进一步明确了二者之间的区分特征,这些特征主要体现前者的Ml～2中脊均发育较弱或无、ml冠面形态较为均一瘦长、ml下前边尖分开程度较大和下颌骨内侧肌肉附着面小孔数量较多等方面。④在分析前人观点的基础上,进一步明确提出Cricetulus极有可能是在晚上新世或早更新世期间从中国北方起源,然后逐渐向周围扩散的。3、归纳整理了中国第四纪期间的化石仓鼠属种,共计8属12种(未含诸多的未定种、相似种、亲近种),此外还有3个存疑种,全部隶属于仓鼠亚科Cricetinae。4、基于对现生标本臼齿特征的观察,给出了中国部分现生仓鼠(共4属6种)的臼齿特征检索表。
[Abstract]:Goat stockaded fossil site is located in Haigang District, Qinhuangdao City, Hebei Province, Yangzhai Village-Limestone quarry. Up to now, four independent fossil sites have been found in the quarry. According to the order from south to north, this article has named the site No. 1, No. 2, No. 3 and No. 4 of the Goat Village in turn. The second site is one of the most abundant fossils, and the fossil abundance is rare in the same period (late Middle Pleistocene or late Pleistocene) fauna in northern China. So far, 55 species of mammals have been found in the site, of which 46 are small mammals, and some are often hundreds of pieces of material. This paper mainly studies the abundant hamster materials collected from this site. The specific research results include: 1. Synthesizing the ages of fauna inferred from the aspects of fauna contrast and absolute age determination, and the recent absolute age measured by ESR (Electron Self-Resonance) method. It is considered that the age of the fauna in the second site of the Yangzhai lies in the late Middle Pleistocene or the late Pleistocene, and the former is preferred to the latter. A total of 1625 hamster materials in the fauna have been systematically studied. In order to compare with fossil materials, more than 200 specimens of present hamster subfamily species were observed. 1 2 genera and 3 species of hamster animals were identified from fossil materials. T. triton in Tscherskia, C.longicaudatus in Cricetulus and C. barabensis in Cricetulus are all present species. 2 the differences and similarities between Cricetinusvarians and T.trion of extinct mutant hamster are compared in detail from three aspects: molar size, shape and construction. The results show that the difference between the two species is very small in the above three aspects. It is concluded that C.varians should be abandoned as a late synonym of T.triton. Since C.varians is a generic species of hamster like Cricetinus, it is considered that Cricetinus should also be abandoned as a late synonym of Tscherskia, which was originally attributed to Cricetinus except C. The other 6 species (C. europaeusus C. gritzaius C. beremendensis C. janossyisia C.koufo.siphon C. mesolophidu.s) should also be transferred to Tscher-skia, and the generic characteristics of Tscherski were given. According to the distribution characteristics and the first time of emergence of Tscher.skia species, it is considered that it may have originated in Europe in the early Pleistocene, and then spread to Asia. The morphology of the anterior tip of two small hamsters under ml and their connections to the posterior anterior ridge may be only a reflection of the age of hamster individuals and have no taxonomic significance. By using the Clongicaudatu. And the present C.barabensis specimens were observed and summarized, and the distinguishing features between them were further clarified. These features mainly show that the middle ridge of Ml~2 in the former has weak or no development, the shape of ml coronal plane is more uniform and thin, the anterior tip of ml is more separated and the number of small foramina of medial mandibular muscle attachment surface is more. 4 On the basis of previous views, It is further pointed out that Cricetulus probably originated from northern China during the late Pleistocene or early Pleistocene, and then gradually spread around. 3. The fossil hamster species during the Quaternary period in China were summarized and sorted out. A total of 12 species belonging to 8 genera (not containing many undetermined species, similar species, close species), in addition to three doubtful species, all belong to the hamster subfamily Cricetinae.4, based on the observation of the characteristics of molars in the present specimen. The retrieval table of molar characteristics of some present hamsters (4 genera and 6 species) in China is given.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q915

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