河北秦皇岛山羊寨哺乳动物群中的兔科动物化石

【作者】 王薇；

【导师】 张云翔；

【作者基本信息】 西北大学 ， 古生物学与地层学， 2009， 硕士

【摘要】 山羊寨哺乳动物群位于河北秦皇岛柳江盆地,化石主要存于一残破的洞穴堆积物中,该动物群主要以小型哺乳动物化石为主,大型哺乳动物化石数量相对有限。在化石采集时,作者等人用筛洗法挑选出可鉴定标本上万件,涉及动物种类包括有食虫目的鼩鼱科Soricidae,鼹鼠科Talpidae,翼手目的蝙蝠科Vespertilionidae,啮齿目的数十种动物、兔形目,及相当一部分低等两栖爬行类的蛙、蛇、蜥蜴和鸟类等。本文通过山羊寨动物群成员的组成特征进行研究,并与更新世典型的华北区动物群-周口店动物群和东北区典型的金牛山动物群进行类比,初步认为山羊寨哺乳动物化石的时代晚于“金牛山下组动物群”,而早于“迁安爪村动物群”和内蒙古“萨拉乌苏动物群”,即时代为中更新世。本论文主要对该动物群中的兔科化石进行研究。本文所论述的兔科化石标本包括84件头骨,158件上颌骨,524件下颌骨,226颗右P2,213颗左P2,136颗右p3及199颗左p3。目前为止共鉴定出兔科3属7种(包括2个未定种),分别为Sericolagus cf.brachypus、?Sylvilagus sp.、Lepus qinhuangdaoensis sp.nov.、东北兔Lepus mandschuricus、Lepus capensis及Lepus sp.。其中秦皇岛兔Lepusqinhuangdaoensis sp.nov.为我国更新世兔类一新种,它是我国目前已知Lepus中个体最小的野兔。Lepus mandschuricus和Lepus capensis化石数量最多,Lepusmandschuricus作为我国北方地区的典型代表,目前仅在金牛山动物群和山羊寨动物群中有化石纪录。Lepus capensis是一个广栖型种类,主要在草原、干旱草原及森林草原等较开阔景观内生活,大量Lepus capensis化石的出现指示出相对干旱的气候条件。山羊寨哺乳动物群的成员具有华北区、东北区、蒙新区混合的现象。根据山羊寨动物群的成员组成及主要兔科化石的生活习性,推断当时化石地点洞穴外草地繁茂,接近水源,毗邻远繁茂的森林区,该地区的环境可能由森林环境逐步过渡至森林草原环境甚至草原荒漠环境,气候由温暖湿润变得稍冷干燥。山羊寨动物群是一个处于过渡区中但更具北方特色的动物群。本论文通过对山羊寨兔科动物的系统分类描述,注重对P2、p3这两个目前重要的分类依据的特征进行更系统的观察总结,结合数量的优势和前人的研究成果,对比邻近动物群中兔科动物化石,为了解我国更新世时期北方地区兔科动物的种类和特点提供了更多的分析材料。同时,本文以山羊寨兔科动物化石p3的形态结构为基础,对山羊寨动物群中的兔科动物的演化关系进行初步讨论,并认为该地区兔科动物的演化在更新世时期呈现多元化的演化趋势,Lepus qinhuangdaoensis sp.nov.与早期种类(如Alilepus)的亲缘关系较我国其他Lepus更近。更多还原

【Abstract】 Shanyangzhai mammalian fauna located in Liujiang Basin, Qinhuangdao, Hebei Province are mainly in the cave sediments. It is dominated by small animal fossils and the large-scale mammal fossils are limited. We had found more than 10000 fossils including Soricidae, Talpidae, Vespertilionidae, Rodentia, Lagomorpha and some species of reptiles.By the study on the composition characteristics of Shanyangzhai mammalian fauna and Comparative analysis with Zhoukoudian Formation fauna and Jinniushan Formation fauna, it indicates that the chronology is later than lower Jinniushan Formation fauna in Liaoning Province and earlier than Qian’an Zhaocun fauna in Hebei Province and Shalawusu fauna in the Inner Mongolia. Based primarily on the rodents and other fossils, the geologic age of the Shanyangzhai Cave is estimated as the Middle Pleistocene.This paper aims at the study on the Leporidae fossils of Shanyanzhai mammalian fauna. In this paper, The Leporidae fossils contains 84 pieces of skulls, 158 pieces of maxilla, 524 pieces of mandible, 226 teeth of right P2, 213 teeth of left P2, 136 teeth of right p3 and 199 teeth of left p3. UP to now, 3 genera 7 species have been identified, including Sericolagus cf. brachypus, ?Sylvilagus sp., Lepus qinhuangdaoensis sp.nov., Lepus mandschuricus, Lepus capensis and Lepus sp.. Lepus qinhuangdaoensis sp.nov. is a new species of Lepus of Pleistocene and it is the smallest Lepus in China. Lepus mandschuricus is typical representative of northern China. It can only be found in Jinniushan fauna before. Lepus capensis is the euryecious type, which often live in steppe, droughty steppe, forest steppe or other open-field environment. A large number of Lepus capensis fossils represent droughty climate. According to the members of Shanyangzhai mammalian fauna and the living habits of these fossils, we inferred that the grassplot is luxuriant out of the cave, and the cave approaches a source of water which adjacent to distant luxuriant forest at that time. Therefore, the environment of this area transits from forest-sylvosteppe to steppe-desert step by step, and the climate transits from warm and moist to cold and mild wet in Middle Pleistocene. Shanyangzhai mammalian fauna is a mammalian fauna with northern features, which located in transitional region. We discussed the systematics of Leporidae in Shanyangzhai mammalian fauna, summed up the characteristic of P2 and p3 which are important basis of classification at present, combined the predominance of amount and previous study results, and compared with other fossils of Leporidae in contiguity mammalian fauna in the thesis. Based on these studies, we can provide more analysis datum for studying the species and characteristics of Leporidae fossils of Middle Pleistocene in northern China. In addition, based on the configuration structure of fossils of Leporidae in Shanyangzhai mammalian fauna, we discussed evolution relationship among the fossils of Leporidae in Shanyangzhai mammalian fauna, and we suggest that the evolution of Lepus in this area is diversifying in Pleistocene. Compare with Lepus in other areas of China, Lepus qinhuangdaoensis sp.nov. has closer kinship with early species (such as Alilepus).更多还原