再论扬子区中、晚奥陶世和志留纪兰多维列世四射珊瑚的源区及对一些珊瑚属的讨论  

RESTUDY OF THE MIDDLE-LATE ORDOVICIAN AND LLANDOVERY RUGOSA SOURCE AREA OF THE YANGTZE REGION WITH A DISCUSSION OF SOME RUGOSE CORAL GENERA

作　　者：何心一[1] 唐兰[2] 

机构地区：[1]中国地质大学,北京100083 [2]广西大学资源与冶金学院,南宁530004

出　　处：《古生物学报》2011年第1期13-31,共19页Acta Palaeontologica Sinica

基　　金：科技部"岩石和化石标本整理整合共享试点"2008项目资助

摘　　要：扬子区中、晚奥陶世和兰多维列世四射珊瑚产出丰富,尤以卡拉道克期(Caradoc)—兰多维列世(Lland-overy)最为繁盛。文中修正厘定的四射珊瑚共113属[包括中奥陶世2属,晚奥陶世25属,兰多维列世86属]。其中有39个属(包括何心一、陈建强,2004已报道的27属和本文新补充的12属)最早出现在扬子区,尔后扩散至中亚、欧洲、北美或其它邻区。新补充12个首现于扬子区的四射珊瑚属,即Yohophyllum,Palaeophyllum,Pseud-ophaulactis,Protopilophyllum,Pilophyllum,Neobrachyelasma,Nanshanophyllum,Paraphillipsastraea,Den-tilasma,Oliveria,Pseudamplexus,Mazaphyllum。根据这些资料,进一步认为扬子区应该是中、晚奥陶世和兰多维列世四射珊瑚起源中心或源区之一。同时论述扬子区中奥陶世—兰多维列世四射珊瑚动物群总体特征及生物古地理关系。该区中奥陶世以穿孔珊瑚类的Calostylis和Yohophyllum为特征。晚奥陶世Ashgill中期珊瑚以下扬子区三衢山组四射珊瑚动物群为代表,其中含某些澳大利亚特有分子——Hillophyllum和Bowanophyllum;而上扬子区Ashgill晚期观音桥层的四射珊瑚动物群与北欧同期珊瑚有高度相似性,这表明两地区有较密切的生物古地理关系。扬子区兰多维列世四射珊瑚动物群与西伯利亚、哈萨克斯坦、澳大利亚等同期的珊瑚动物群(参见本文插图1)有较密切的关系。而在兰多维列世扬子区与中亚塔吉克斯坦同期珊瑚动物群也较密切,可属于同一生物地理区——中亚与华南区。此外,文中特别对8个属种加以讨论和描述并附相关图影,它们是:Neobrachyelasmasp.aff.balchashicum Nikolaeva,Amsdenoidessp.,Nanshanophyllum sp.,Idiophyllumtenlatum(Jin),Paraphillipsastraea jianbaoensisJin,Stylopleura sp.,Schlothei mophyllumsp.,Mazaphyllum sp.。The Middle Ordovican to Llandovery rugose corals are abundant in the Yangtze Region,especially in the Llandovery（Aeronian—Telychian）.Altogether 113 genera of Rugosa have been reported from the region comprising two genera from the Middle Ordovician,25 genera from the Late Ordovican and 86 from the Llandovery,about 39 genera [including 27 genera reported by He and Chen（2004）,and a further 12 in this paper] first made their appearance in the Yangtze Region from where they dispersed to Central Asia,Europe,North America and other adjacent regions.The 12 additional genera reported here paper as having their earliest occurrence in the Yangtze Region are Yohophyllum,Palaeophyllum,Pseudophaulactis,Protopilophyllum,Pilophyllum,Neobrachyelasma,Nanshanophyllum,Paraphillipsastraea,Dentilasma,Oliveria,Pseudmaplexus and Mazaphyllum.Together with precious records,this new material strengthens our view that the Yangtze Region was a centre of origin for Middle-Late Ordovician and Llandovery rugose corals.The Middle Ordovician Rugosa of this region are characterized by the calostylids Calostylis and Yohophyllum.The Late Ordovician rugosan fauna from the Sanjushan Formation of western Zhejiang Province,on the other hand,contains some Australian elements（Hillophyllum and Bowanophyllum）, whereas latest Ordovician rugose coral fauna from the Kuanyinchiao Bed in the Upper Yangtze Region is very similar to that of North Europe,indicating that the Yangtze Region and North Europe had a close palaeobiogeographic affinity with each other at that time.The Llandovery rugose fauna of the Yangtze Region however is much more similar to that of Siberia,Kazakhstan,Australia and SW Japan,possessing some genera in common（see TableⅠ）.Eight rugosan genera and species are described and illustrated： Neobrachyelasma sp.aff.balchaschicum Nikolaeva,Amsdenoides sp.,Nanshanophyllum sp.,Idiophyllum tenlatum（Jin）,Paraphillisastraea jianbaoensis Jin,Stylopleura sp.,Schlotheimophyllum sp.and Mazaphyllum sp.

关 键 词：四射珊瑚 中、晚奥陶世 兰多维列世 扬子区 源区 生物古地理 

分 类 号：Q915[天文地球—古生物学与地层学]