湖北宜昌寒武系水井沱组古杯化石上蓝菌类及其微型钻孔  

CYANOBACTERIA FOSSILS AND THE MICROBORINGS ON THE ARCHAEOCYATHIDS FROM THE SHUIJINGTUO FORMATION OF THE CAMBRIAN(SERIES 2),YICHANG,HUBEI PROVINCE

作　　者：王相人[1] 张志飞[1,2] 韩健[1] 

机构地区：[1]西北大学地质学系大陆动力学国家重点实验室早期生命研究所,西安710069 [2]中国科学院南京地质古生物研究所现代古生物学与地层学国家重点实验室,南京210008

出　　处：《微体古生物学报》2012年第2期170-178,共9页Acta Micropalaeontologica Sinica

基　　金：国家自然科学基金项目(41072017);中国科学院现代古生物学与地层学国家重点实验室;霍英东教育基金(G121016);教育部全国优秀博士论文作者专项基金;西北大学大陆动力学国家重点实验室研究生实验资助经费共同资助

摘　　要：湖北宜昌下寒武统水井沱组灰岩中富含大量壳体化石,主要包括腕足动物以及少量古杯化石。研究发现部分古杯化石表面保存丰富的微生物个体及其微型钻孔,同时发现有的微型钻孔内原位保存微生物个体,这种保存方式表明微生物体与微型钻孔之间具有直接联系。微生物体呈丝管状,空心,弯曲程度不等,横切面呈圆形,直径约7—10μm,长度可达500μm。钻孔直径15—25μm,横截面为圆形。微钻孔保存在古杯板间室(intersept)内,大多与板间室侧表面平行,少数与板间室侧表面斜交。形态研究表明这些微生物体可能为钻孔蓝菌类Endoconchialata。古杯骨骼上发现的这些微型钻孔及其原位保存的蓝菌类化石的研究对理解前寒武纪-寒武纪界线附近发现的微型钻孔化石的成因和生物属性有重要启示。The Cambrian is well-exposed and widely developed at Yichang of the Three Gorges area, Hubei Province. A fauna of ahundant Small Shelly Fossils was yielded in the limestone of the upper portion of the Shuijingtuo Forma tion, comprising dominated brachiopods, hyoliths, anabaritiids, sponge spicules, and some archaeocyathid fragments. On the surface of some fragmental archaeocyathids, large number of microborings with in situ preservation of microbes were revealed. The microbes filaments range from 7--10 μm in＊diameter, and up to 500 μm in the maximal length. By contrast, the micromorphic boreholes discovered in the fossil archaeocyathids varies between 15--25 μm in diameter. Some microborings in situ preserved microorganisms （Endoconchia lata） in the life position. The skeletons of archaeoeyathid were preserved as phosphate, and microborings and microorganisms were also directly phosphatized during early diagenesis. Morphological study suggests that the microbes could be endolithic cyanobacteria Endocon- chin lata. The discovery of the endolithic microbe cyanobacteria enclosed in the microborings is benefit to understanding the origin and biglogical affinity of microborings distributed near the Precambrian-Cambrian boundary.

关 键 词：蓝菌类Endoconchia 古杯 微钻孔 寒武纪 湖北 

分 类 号：Q915[天文地球—古生物学与地层学]