贵州台江五河剖面灯影组顶部微体动物化石

贵州台江灯影组白云岩中发现了30～70μm的锥形微体动物化石,它们具有典型的锥管状、似几丁质壳壁和平行纤维结构等生物结构,可能分属软体动物Carinachitids、Arthrochites、Punctatus、Spondylotubus和似几丁虫类化石等5种类型。其中建立了一新属、种Spondylotubus taijiangensis Yang(gen.etsp.nov.)。在灯影组白云岩中这一类群的发现对研究前寒武纪寒武纪界线附近生物的多样性和生物地层,以及寒武纪生物大爆发都具有一定的科学意义。

MICROFOSSILS FROM THE DENYING FORMATION OF WUHE SECTION, TAIJIANG COUNTY, GUIZHOU PROVINCE, CHINA

A new microfossil assemblage was discovered from the Dengying Formation, Upper Sinian of the Wuhe section, Taijiang County, Guizhou Province, with a cone- and tube-shaped and 30～70 μm long. They were considered as Carinchitiids, Hexangulaconulariids and Punctatus. Furthermore, a new microfossil taxon with cone-tube and thin shell, was discovered from the upper dolomites of Dengying Formation. It was Spondylotubus taijiangensis Yang(gen. et sp. nov.). Based on the discoveries, it was suggested that the Precambrian-Cambrian boundary would be located at the base of upper dolomites of the Dengying Formation, which was concord with the boundary of Precambrian-Cambrian in Yunnan, Sichuan and Shaanxi Provinces. The microfossils from Late Sinian Dengying Formation in Guizhou were similar to small shall skeletal in morphology, but size of the microfossils were smaller than that of small shall skeletal in early Cambrian. The microfossils might indicate an inhabiting taxa in deeper shelf. This discovery was helpful to study on early Cambrian evolution of metazoan, and the boundary of Precambrian-Cambrian.