Paleobiogeographic patterns of the brachiopod faunas before and during the first radiation of the Great Ordovi-cian Biodiversification Event(GOBE)in South China at 6 different localities from the upper Jiangnan Slope ...Paleobiogeographic patterns of the brachiopod faunas before and during the first radiation of the Great Ordovi-cian Biodiversification Event(GOBE)in South China at 6 different localities from the upper Jiangnan Slope to the vast area of the Upper Yangtze Platform show several interesting features.First,the initial brachiopod diver-sity acme was accompanied by both high origination and extinction rates.Second,no significant changes took place in the taxonomic composition and paleobiogeographic pattern of the brachiopod fauna during the radia-tion at 5 of the 6 localities studied except the near shore locality,where the first brachiopod radiation was much later than at other localities and was marked by a dramatic increase in endemic constituents.Third,orthides were the predominant brachiopod group during the radiation,and regional brachiopod taxa played a significant role in defining the paleobiogeographic pattern of the radiation.Fourth,the first brachiopod radiation was asso-ciated with 3 major pulses of onshore migration from the upper Jiangnan Slope through the central Upper Yang-tze Platform to the near shore settings of the platform,with the middle pulse being the most significant.Finally,paleogeographic dispersal took place in both onshore and offshore directions,although the onshore expansion was more prominent;several key brachiopods,such as Paralenorthis,Nocturnellia,Protoskenidioides,Nere-idella,Euorthisina and Yangtzeella,first appeared on the upper Jiangnan Slope and later formed distinct,and taxonomically diverse,communities on the Upper Yangtze Platform.The paleogeographic dispersal of brachio-pods is considered to be closely related to the tectonic evolution of the Qianzhong Arch.展开更多
基金Financial support for this study was received from the National Natural Science Foundation of China(40825006,41221001 and 41290260)the Ministry of Science and Technology,the Chinese Academy of Sci-ences and the State Key Laboratory of Palaeobiology and Stratigraphy,the Visiting University Scholars Pro-gram of Western University(Canada)and the Natural Sciences and Engineering Research Council of Canada.This paper is a contribution to IGCP project 591,‘The Early to Middle Paleozoic Revolution’.
文摘Paleobiogeographic patterns of the brachiopod faunas before and during the first radiation of the Great Ordovi-cian Biodiversification Event(GOBE)in South China at 6 different localities from the upper Jiangnan Slope to the vast area of the Upper Yangtze Platform show several interesting features.First,the initial brachiopod diver-sity acme was accompanied by both high origination and extinction rates.Second,no significant changes took place in the taxonomic composition and paleobiogeographic pattern of the brachiopod fauna during the radia-tion at 5 of the 6 localities studied except the near shore locality,where the first brachiopod radiation was much later than at other localities and was marked by a dramatic increase in endemic constituents.Third,orthides were the predominant brachiopod group during the radiation,and regional brachiopod taxa played a significant role in defining the paleobiogeographic pattern of the radiation.Fourth,the first brachiopod radiation was asso-ciated with 3 major pulses of onshore migration from the upper Jiangnan Slope through the central Upper Yang-tze Platform to the near shore settings of the platform,with the middle pulse being the most significant.Finally,paleogeographic dispersal took place in both onshore and offshore directions,although the onshore expansion was more prominent;several key brachiopods,such as Paralenorthis,Nocturnellia,Protoskenidioides,Nere-idella,Euorthisina and Yangtzeella,first appeared on the upper Jiangnan Slope and later formed distinct,and taxonomically diverse,communities on the Upper Yangtze Platform.The paleogeographic dispersal of brachio-pods is considered to be closely related to the tectonic evolution of the Qianzhong Arch.
