Mechanism on bipolar distribution of Permian brachiopods  

作　　者：Chengwen WANG Songmei ZHANG 

机构地区：[1]College of Earth Sciences, Jilin University, Changchun 130026, China [2]College of Resources Science ＆ Technology, Beijing Normal University, Beijing 100875, China

出　　处：《Global Geology》2008年第2期59-77,共19页世界地质（英文版）

基　　金：Supported by Project of Doctoral Program of Ministry Education (No.20060183023)

摘　　要：By reasearch on geographic distribution, nine genera in bipolar distribution are selected from Permian brachiopods. These taxa originated from middle-high latitude areas in the boreal realm, of which five genera were derived from Late Carboniferous, and other four genera originated from Permian. They were all in bipolar distribution during some different stages in Permian. Specific diversity for each genus was high in the boreal realm, whereas in the Gondwana realm was very low. Perdurability was long in the boreal realm, and short in the Gondwana realm. It was the time when these nine genera came to their maximum diversity that these genera appeared in the Gondwana and formed bipolar distribution; while they also migrated to the low latitude from high latitude. This shows very close relationship between several main cooling events in Permian and the migration of genera from the boreal realm to the Gondwana reahn through the Tethys. Therefore, the cooling events might be the main drive which caused these cold-water-type brachiopods migrated to the Gondwana realm and being bipolar distribution. In this process, the planula tolerance to warm water would be another important factor.By reasearch on geographic distribution,nine genera in bipolar distribution are selected from Permian brachiopods.These taxa originated from middle-high latitude areas in the boreal realm,of which five genera were derived from Late Carboniferous,and other four genera originated from Permian.They were all in bipolar distribution during some different stages in Permian.Specific diversity for each genus was high in the boreal realm,whereas in the Gondwana realm was very low.Perdurability was long in the boreal realm,and short in the Gondwana realm.It was the time when these nine genera came to their maximum diversity that these genera appeared in the Gondwana and formed bipolar distribution;while they also migrated to the low latitude from high latitude.This shows very close relationship between several main cooling events in Permian and the migration of genera from the boreal realm to the Gondwana realm through the Tethys.Therefore,the cooling events might be the main drive which caused these cold-water-type brachiopods migrated to the Gondwana realm and being bipolar distribution.In this process,the planula tolerance to warm water would be another important factor.

关 键 词：PERMIAN BRACHIOPOD bipolar distribution MECHANISM 

分 类 号：Q951[生物学—动物学]