安徽石台奥陶纪弗洛期-大坪期牙形刺多样性的演变  

CONODONT DIVERSIFICATION IN THE ZITAI FORMATION(FLOIAN-DAPINGIAN,LATE EARLY-EARLY MID ORDOVICIAN) OF SHITAI,ANHUI PROVINCE,EAST CHINA

作　　者：吴荣昌[1,2] 詹仁斌[1] 李贵鹏[1,2] 

机构地区：[1]现代古生物学和地层学国家重点实验室,中国科学院南京地质古生物研究所,南京210008 [2]中国科学院研究生院,北京100049

出　　处：《古生物学报》2008年第4期444-453,共10页Acta Palaeontologica Sinica

基　　金：中科院创新工程重要方向项目(KZCX3-SW-149);国家基金委基金项目(40532009);科技部973项目(2006CB806402)资助

摘　　要：基于安徽石台栗阳柳树亭下、中奥陶统紫台组牙形刺的系统研究,对该地区早奥陶世弗洛期-中奥陶世大坪期牙形刺多样性演变作了初步分析,发现牙形刺的简单分异度在弗洛晚期Oepikodus evae带达到峰值,有17属20种。之后,牙形刺分异度呈下降趋势。演变的总体趋势与湖北宜昌地区同期牙形刺的研究结果一致,其峰值出现的时间(Oepikodus evae带,相当于笔石Didymograptelluseobi fidus带上部,Corymbograptus deflexus带,及Azygograptus suecicus带下部)与华南上扬子区腕足动物宏演化趋势(首次峰值出现在Didymograptellus eob-ifidus带)大体相似,但比三叶虫多样性演变在奥陶纪的首次峰值(出现在Exigraptus clavus带)早,比扬子台地笔石多样性演变的首次峰值(在Acrograptus filiformis带和Didymograptellus eobifidus带下部)晚。分析显示,该地区早、中奥陶世牙形刺多样性演变与海平面变化存在密切关联。Based on the preliminary research of the conodonts from the Zitai Formation at Liushuting Section, Shitai County, the conodont biodiversity changes during the Floian and the Dapingian are discussed according to the conodont biozones. The Ordovician conodont radiation in the study area got its first acme during the Oepikodus evae Biozone, which was consistent with the macroevolutionary trend of braehiopods in South China. The braehiopod faunas had their first biodiversification acme in the graptolite Didymograptellus eobifidus Biozone, roughly corresponding to the middle part of the conodont Oepikodus evae Biozone. Trilobites of South China radiated much later and got their first diversity acme in the Ezigraptus clavus Biozone （late Dapingian, Mid Ordovician）. In contrast, the graptolites had a much earlier biodiversification trend with its first acme in the Acrograptus fili formis Biozone and Didyrnograptellus eob- ifidus Biozone on the Yangtze Platform. After the first biodiversification, the conodont diversity on the Yangtze Platform decreased gradually. Through the correlation with the sea-level fluctuation of South China Block, the authors suggest that the conodont diversity changes might be partially controlled by the sea-level fluctuations.

关 键 词：牙形刺 多样性 紫台组 弗洛期-大坪期 奥陶纪 石台 

分 类 号：Q915[天文地球—古生物学与地层学]