贵州凤冈早志留世孢子组合的发现及其古植物学意义

GASTROPODS FROM FENTOU FORMATION OF JIANGSU AND ANHUI PROVINCES

系统描述贵州凤冈早志留世的孢子５属１２种（类型），其中包括１新种。根据其组合特征，确认其时代为Ｌｌａｎｄｏｖｅｒｉａｎ晚期。通过对三缝孢的性状分析，认为在早志留世Ｌｌａｎｄｏｖｅｒｉａｎ晚期已确有维管植物的存在。

The Silurian gastropods described and discussed here were collected from the upper part of the Fentou Formation in Tangshan, Nanjing of Jiangsu, Chaoxian of Anhui, and some other places. These gastropods contain 12 species in 11 genera, associated with the trilobites Coronoce phalus and Kailia; the cephalopod Sichuanoceras; the branchiopod Salopina, the pelecypod Orthonota perlata; and the chitinozoa Angochitina longicollis, all of which are often seen in the Xiushan Formation on the Upper Reaches of the Yangzi River, under the name of the Coronocephalus Salopina Orthonota perlata Angochitina longicollis Assemblage. Among these gastropods, Umbonellina cf. globulosa Yu, Raphistomina rhombistoma Yu and Trochonema (Trochonema) cf. fragile Ulrich et Scofield are the elements often seen in the upper part of the Xiushan Formation, the upper Wengxiang Group and the Shiniulan Formation in Southwest China. Therefore, the upper Fentou Formation may compare with the Upper Xiushan Formation, both belonging to the Early Silurian in age.