桂北地区早石炭世杜内期长身贝类的发现及其生物古地理意义  

Productoid brachiopods from the Tournaisian of Lower Carboniferous in northern Guangxi,South China:Discovery and their biopalaeogeographical significance

作　　者：王海涛[1] 孙元林[1] 陆济璞[2] 

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]广西区域地质调查研究院,广西桂林541003

出　　处：《古地理学报》2006年第4期539-550,共12页Journal of Palaeogeography：Chinese Edition

基　　金：科技部国家重点基础研究发展计划项目(G2000077700);自然科学基金项目(40272005和40572004)

摘　　要：在广西北部兴安县高尚镇金子山剖面下石炭统鹿寨组底部,新发现了长身贝类腕足化石,包括1新种、1相似种、6未定种和2属种未定类型。这些长身贝类以Productellidae和Productidae科的分子为主,另有少量Echinoconchidae和Monticuliferidae科的分子。这些长身贝类全部属于生活在静水环境中的薄壳类型,无一与华南同期地层中已知类型相同。它们之间的差异可能反映了不同沉积环境条件对腕足动物群属种的控制。在鹿寨组底部发现的长身贝类以及近年在桂林南边村和黔南睦化剖面腕足动物群的发现显示出华南台缘斜坡—盆地相区杜内阶中的腕足动物群具有极高的属种分异度,不但有大量见于世界其他地方同期动物群中的分子,也包含有不少原本认为只在维宪阶或更高层位出现的类型或全新的类型,说明华南台缘斜坡—盆地相区不但与世界其他地区的腕足动物群之间存在密切的生物地理区系联系,而且华南台缘斜坡—盆地相区是杜内期腕足动物起源和辐射演化的重要策源地之一。许多属种可能是在这里起源,并迁移扩散到其他地方。The Tournaisian productoid brachiopods, discovered at the base of the Luzhai Formation of the Jinzishan Section, Xing＇an county, Guangxi, South China, including a new, a conformis and six indeterminate species, plus two forms described in open nomenclature, were described in this paper. These productoids are dominated by the forms of the families Productellidae and Productidae, and have only a few representatives of the echinoconchids and monticuliferids. All of the productoids belong to thin-shelled types dwelling in a low-energy environment and none has been recorded in other places of South China. The difference on the productoid brachiopod composition between the Jinzishan Section and other places in South China probably resulted from their different environmental controlling. The productoids from Xing＇an and the data recently discovered from the Nanbiancun of Guilin and Muhua of south Guizhou revealed that the Tournaisian brachiopod fauna in the slope margin to basinal facies of South China has an exceptionally high taxonomic diversity. It not only has abundant forms that characterizes the Tournaisian brachiopod faunas out of South China, but also contains many taxa that are new or previously considered to be stratigraphically restricted in horizons higher than the Tournaisian Stage. It is suggested that the slope margin to basinal facies of South China not only has a close biogeographical relationship with other places of the world, but also is one of the important origination and radiation centers of the brachiopods during the Tournaisian, from which many new genera and species are originated and then migrated to spread all over the world.

关 键 词：长身贝类 腕足动物 生物古地理 鹿寨组 杜内阶 下石炭统 桂北 

分 类 号：Q911.5[天文地球—古生物学与地层学]