中国古生代中期盔甲鱼类及其古地理意义  

Galeaspid of the Middle Paleozoic in China and its palaeogeographic significance

作　　者：赵文金[1] 

机构地区：[1]中国科学院古脊椎动物与古人类研究所,北京100044

出　　处：《古地理学报》2005年第3期305-320,共16页Journal of Palaeogeography：Chinese Edition

基　　金：国家重点基础研究发展规划项目(编号:G2000077704);国家自然科学基金重点项目(编号:40332017);国际地质对比计划IGCP491项目资助

摘　　要：盔甲鱼类是古生代中期化石无颌类的主要类群,其分布主要限于我国境内以及越南北部。至目前为止,在我国已发现并鉴定的盔甲鱼类计有48属68种,其中志留纪14属19种,遍布川、陕、鄂、湘、皖、浙、赣、新等省(区);泥盆纪35属49种,遍布宁、川、黔、桂、滇等省(区)。本文不仅对含盔甲鱼类的地层进行了详细的对比研究,而且根据盔甲鱼类在中古生代地层中出现的先后顺序,自下而上划分了9个盔甲鱼化石组合与1个盔甲鱼层,并认为这些化石组合和盔甲鱼层之间的演替与当时环境条件的变化及古地理、古构造的变迁密不可分。另外,通过对盔甲鱼类形态学及古生态学的研究,认为盔甲鱼类应是一类行底栖滤食性生活、运动能力不强的类群,其主要生活环境为靠近古陆边缘的海域。由于其迁移扩散能力有限,宽广的陆地以及宽阔的海洋均成为其迁移、扩散的障碍,因此盔甲鱼类具有重要的古生物地理意义。最后,根据盔甲鱼类在我国的地理分布特征,并结合大地构造学及古地磁学方面的资料,对中古生代我国三大主要板块之间的古地理关系进行了初步的探讨性研究,结果表明古生代中期中国三大板块具有十分密切的古地理关系,它们彼此相接或相邻,并同属于一个鱼类动物地理区系即泛华夏盔甲鱼类区系。The Galeaspid is one major group of Agnatha in the Middle Paleozoic, and is mainly distributed in China and North Vietnam. Up to now, the fossil galeaspid agnathans found and described in China can be attributed to 68 species in 48 genera. 19 species in 14 genera of them are referred to the Silurian galeaspid agnathans, and are mainly distributed in Sichuan, Shaanxi, Hubei, Hunan, Anhui, Zhejiang, Jiangxi provinces and Xinjiang Autonomous Region .49 species in 35 genera of them are referred to the Devonian galeaspid agnathans, and are mainly distributed in Sichuan, Guizhou, Yunnan provinces and Ningxia, Guangxi autonomous regions . The author firstly studied in detail the Middle Paleozoic galeaspid agnathans in China and the related correlation of galaespids-bearing strata. According to the occurrence orders of the Middle Paleozoic galeaspids, nine galeaspid agnathans assemblages and one galaespids-bearing stratum can be recognized from the Early Silurian to the Late Devonian in China. The succession of the Chinese galeaspid agnathans assemblages is closely related to the changes of palaeoenvironment, palaeogeography and palaeoconformation. Secondly, according to the study on the morphology and palaeoecology of galeaspids, most of them dwelt in the sea area close to palaeocontinents margin, including delta and estuary, and lived a benthic life as filter feeder.Both the continents and expansive oceans became the major obstacles for their migration and dispersal because of their limited locomotory and dispersal capabilities, and thus galeaspids are biogeographically useful. Lastly, based on the distribution of the Chinese galeaspid agnathans, and some information of the plate tectonics and palaeogeomagnetism, the study reveals that the palaeogeographical relationships among three major eastern Asian blocks （i. e. the South China, the North China and the Tarim blocks） are very close during the Middle Paleozoic. They were linked or neighboured near each other, and shared a highly endemic vertebrate fauna, namely

关 键 词：盔甲鱼类 古地理 古生代中期 中国 古生代地层 中期 化石组合 地理分布特征 生活环境 扩散能力 

分 类 号：P542[天文地球—构造地质学] Q915.862[天文地球—地质学]