湖北宜昌奥陶纪大湾组的三叶虫新种Ovalocephalus eoprimitivus sp. nov.(英文)  

A NEW ORDOVICIAN TRILOBITE OVALOCEPHALUS EOPRIMITIVUS SP. NOV. FROM THE DAWAN FORMATION,YICHANG,WESTERN HUBEI

作　　者：周志毅[1] 周志强[2] 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008 [2]西安地质矿产研究所,西安710054

出　　处：《古生物学报》2008年第4期454-456,共3页Acta Palaeontologica Sinica

基　　金：国家重点基础研究发展计划项目(2006CB806402);国家自然科学基金(40532009);中国科学院知识创新工程重要方向项目(KZCX3-SW-149)资助

摘　　要：本文记述湖北宜昌地区奥陶纪大湾组下部的一个三叶虫新种Ovalocephalus eoprimitivus sp.nov.,主要特征是头鞍缺失前颈环横沟。Ovalocephalus Koroleva为泛冈瓦纳的标志分子,在中国奥陶系分布极为广泛。这一新种的时代为弗洛期—大坪期,系该属目前所知地层层位最低的分子。The trilobite genus Ovalocephalus Koroleva, 1959 （=Hammatocnemis Kielan, 1960） has long been considered to be biogeographieally significant. It was endemic to peri-Gondwana and especially widely spread in China during the Or dovician （Lu and Zhou,1979; Zhou and Dean, 1989）. Its earliest species previously known is Ovalocephalus primitivus （Lu） with the hol- otype eranidium （Lu, 1975, pl. 45, fig. 7） recorded from the upper Dawan Formation （early Darriwilian） of the Yichang area. Recently, some new material of the genus was gained from the lower part of the Dawan Formation （Floian-Dapingian） in the same area （Turvey and Zhou, 2002; Wang etal. , 2005）. After a eritical study on these specimens, we believe that they should be referred to a new species, and may represent an ancestral form of Ovalocephalus.

关 键 词：Ovalocephalus eoprimitivus sp.nov. 三叶虫 奥陶纪 宜昌 

分 类 号：Q915[天文地球—古生物学与地层学]