【作者】 张琬茜；

【导师】 李勇；

【作者基本信息】 长安大学 ， 古生物学与地层学， 2007， 硕士

【摘要】 瓮安生物群产出于贵州省瓮安县,赋存于距今约六亿年的上震旦统陡山沱组含磷地层中。它以真核生物为主体,是处于寒武纪生物大爆发前夜立体保存的磷酸盐化生物群,是当前国内外古生物学领域的研究“热点”之一。本论文以其中的微管柱状化石为研究对象,着重讨论了其多样性的形态结构及形态分类等问题。微管柱状化石的研究目前还处于起步阶段,随着化石类型的不断增加,其中出现的问题也越来也多。笔者在采集了大量生物化石的基础上,对三百多枚管柱状化石的形态、结构等特征进行了认真的分析研究和仔细的描述,发现该类型化石在形态、结构方面存在着许多特征性差异,包括前人纳入同一属种的化石体之间,也存在较大差异。有关腔肠动物和棘皮动物的争议,实际上也是形态结构明显不同的两种类型。针对这种现象,笔者认为在对早期生物化石不能确定生物属性的情况下,其形态学分类是必要且可行的研究方法,是基础性的工作。本论文基于形态结构的对比分析,并参考前人化石资料,首次对本区微管柱状化石提出了一套形态分类方案,并提出了微管柱状化石形态分类研究的几项新观点和新思想。形态分类是生物分类的基础,一定的生物种属应当具有特定的形态结构,结构和形态的差异往往预示着生物物种的本质不同。该时期的生物正处于生命发展的初期阶段,物种分化也刚刚起步,分异度不太明显。相似性较多反映了初生生物演化的同源性,微小的差别则代表着原始生物向不同方向分异演化的初始性。正是由于该生物群处于生物大的辐射之前的特殊性,这些小的差异很可能会成为生物体千差万别的起始点,促使它们走上不同的发展演化方向。因此,这些差异是早期生物的重要特征,也是对其深入研究的依据。笔者对管柱状化石的一些类型做了生物属性上的探讨和对比研究,并提出了自己的新看法。在研究过程中共发现了8种未见报道过的化石新个体,为早期生命研究提供了新资料。更多还原

【Abstract】 Weng’an biota is distributing in upper Sinian Doushantuo Formation Weng’an county, Guizhou, China, which are composed of diversiform three-dimensional phosphatized microfossils, mainly of eukaryote, ranging from about 600Ma. It provides an unusually clear window on biological diversity before the Cambrian Explosion. It has been one of the focus in the international paleontology study, due to it’s important status in the life evolution. The principal of this paper is to make a systematic study on the cylindrical and tubular microfossils of this biota, to focus our mind on their diversity and morphological classification.The study of the cylindrical and tubular microfossils is in initial stage at present. With the fossil types increasing, more and more question occur. Based on the careful observing of more than 300 cylindrical and tubular microfossils, the author found that there are essential diversity in forms and conformation between these cylindrical and tubes microfossils, same thing in the fossils which the predecessor concluded the same type. In view of this phenomenon, morphological classification is necessary and feasible method when the early biology fossil cannot decide in its biological genus. This is the foundational work in the early life study.Refers to the predecessor fossils,the article gives us some new opinions or perspectives based on carefore observation.Morphological classification is the basic work of the classification in biological attribute. Each species has it’s distinct characteristics in fome and structure. The comparabilitys between species determining their kindred relationship. The little difference was been urges the evolution development to the different direction. We must attach more importance to the differents in fome and structure, because the biota is living in the moment that early species variation just began happening. The diversity, even very small different in fome and structure may be the point of new species’ start.The possibilities of biological species are respectively discussed by own attitude in thispaper, 8 species which are new observation included.更多还原