【作者】 文芠；

【导师】 赵兵； 张启跃；

【作者基本信息】 成都理工大学 ， 古生物学与地层学， 2011， 硕士

【摘要】 罗平地区在中三叠世安尼期时期的古地理位置位于康滇古陆以东,南盘江盆地以西。由于中三叠世开始,在印支运动的作用下,在靠近康滇古陆一侧的扬子碳酸盐岩台地上在印支运动的推动下出现了一系列台内凹陷,罗平地区就是其中之一。罗平生物群保存在中三叠统关岭组二段薄层泥晶灰岩中,生物种类丰富,数量繁多,包含海相脊椎动物、节肢动物、棘皮动物、软体动物、陆相植物以及一些分类未定的化石。其物种多样性大大超过了华南海相关岭生物群、兴义贵州龙动物群以及盘县动物群。鱼类化石是脊椎动物化石的最主要的组成部分,具有重要的研究意义。罗平生物群鱼类化石种类丰富,有Palaeonisciformes(古鳕目)、Saurichthyiformes(龙鱼目)、Peltopleuriformes(肋鳞鱼目)、Perleidiformes(裂齿鱼目)、Semionotiformes(半椎鱼目)、Coelacanthiformes(空棘鱼目)以及一些非半椎鱼类的新鳍鱼类等。本文分别对这些类别进行了系统描述,并建立了两个新属新种即Luoxiongichthys hyperdorsalis gen. et sp. nov. (高背罗雄鱼)和Luopingcoelacanthus eurylacrimalis gen. et sp. nov. (宽泪颧骨罗平空棘鱼)。针对实测剖面上石坎剖面的三大鱼类化石的个体数进行统计并绘出比例饼状图和比例变化规律直方图,直观的反应了上石坎剖面三大鱼类化石组构关系。新鳍鱼类在整个鱼类化石总数中占有相当大的比例,且种类繁多,这证明了在中三叠世安尼期新鳍鱼类已经开始全面辐射。本文以上石坎剖面31层面上富集的鱼类化石作为依托,进行埋藏学特征研究。通过一系列的证据证明了罗平生物群鱼类化石属于原地埋藏。保存完好和关联好的鱼类化石对应的是灰黑色薄层到纹层状泥质灰岩或泥晶灰岩中,指示了一个安静、缺氧的底部环境。罗平生物群的生物具备了从初级生产者到初级消费者,再到高级消费者,最后再到分解者的全部类别,已经形成了一个健康完整的食物链。本文在辅助剖面的测制(马场剖面、裸可剖面、小寨剖面、四方石剖面、金歹剖面和门前坡剖面)和野外化石层位露头的基础上,恢复了罗平生物群的生态环境。首先确定了罗平生物群化石产出的核心区域,然后从化石分布核心区向外围追溯,探明了罗平台内盆地的东西界限,进一步限定了罗平台内凹陷的范围。罗平台内凹陷西至阿梅者-茶安-勒泥朵,再向西便是泸西台内凹陷;东至土地庙、蚌山和八大河过渡到南盘江盆地。罗平台内凹陷为种类丰富的海洋生物提供了一个安乐窝。更多还原

【Abstract】 The palaeogeographic location of Luoping area in Middle Triassic period located between the east of Kangdian old land and the western edge of Nanpanjiang basin. In the period of Middle Triassic, there was a series of small sags within the platform distributed on the Yangtze carbonate platform under the function of Indo-China Orogeny. Luoping area was one of the sag within the platform.Luoping Biota was preserved in the laminated micritic limestone, which belong to the second member of Guanling Formation, Middle Trassic. Various fossils have been found in Luoping Biota including marine vertebrates, arthorpods, echinoderms, mollusk, continental plants as well as some undetermined species. And its species diversity is much more than the Guanling Fauna, Xingyi Fauna and Panxian Fauna in Southern China. Among the vertebrate fossils, fish fossils are the main part. As a result, studing on the fish fossils is of great significance to the research of the whole biota. Luoping Biota has a great variety of fish fossils. There are Palaeonisciformes, Saurichthyiformes, Perleidiformes, Peltopleuriformes, Semionotiformes, Coelacanth- iformes and some non-semionotiformes neopterygians. This thesis describes those different types respectively. Some of them is new genus and species, for example, Luoxiongichthys hyperdorsalis gen. et sp. nov. and Luopingcoelacanthus eurylacrima- lis gen. et sp. nov.In order to reflect the proportion of the three typical types of fish fossils, we do the statistic analysis and draw the histogram on the basis of those fish fossils from Shangshikan Section. It is proved that the neopterygian take a great proportion in the total number. That is to say, neopterygian began to radiate in the Middle Triassic.The taphonomic features of fish fossils is studied based on the 31th. layer of Shangshikan Section. It is proved that they all preserved at the orignal places. Most of well-preserved fish fossils correspond to grey-black laminated micrite and muddy limestone. It indicates undisturbed and anoxic bottom environment.Different fossils play different roles in Luoping Biota. From the primary producer, primary customer, senior customer to decomposer, Luoping Biota has a healthy food chain. On the basis of assistant sections (Machang Section, Luoke Section, Xiaozhai Section, Sifangshi Section, Jindai Section and Menqianpo Section) and fossil outcrop, we recover the paleoenvironment of Luoping Biota. Firstly, we determine the key area which has the fossil layers on the basis of the fossil outcrop. Secondly, we observe the outarea from the key area and find the scope of Luoping sag within the platform. The western boundary is along the Ameizhe-Chaan-Leniduo village. Beyond the western bountary is the Luxi sag within platform. The eastern boundary is along Tudimiao-Bengshan village. The eastern Badahe is turbidity deposite, making the transition from platform to Nanpanjiang Basin. The Luoping sag within platform provides a fantastic home for marine lives.更多还原