贵州岑巩羊桥罗家塘杷榔动物群的发现及其后生动物早期演化的意义

Discovery of the Balang Fauna at Luojiatang,Yangqiao,Cengong,Guizhou,and Its Significance to the Early Evolution of the Metazoa

岑巩县羊桥乡罗家塘杷榔组仅出露中-上部地层,岩性单一,均为青灰、灰绿色粉砂质泥、页岩。在其上部层位发现了俞氏贵州始海百合(Guizhoueocrinus yui Zhao,Parsley et Peng,2007),计有棘皮动物始海百合、腕足动物、软体动物——软舌螺、节肢动物--三叶虫等8属9种,包括了2个未定名的新种和1未定种,与凯里市杷榔组的杷榔动物群相似。新的发现扩展了杷榔动物群的地理分布,提供了群落生态及埋藏学研究的新材料,具有重要的科学和实践意义。

Here we report the discovery of the Balang Fauna from a new locality of the Balang Formation at Luojiatang village,Yangqiao Town,Cengong County.At the Luojiatang locality,only the middle and upper parts of the formation are exposed.The section is comprised of a monofacial succession of grey silty shales and silty calcareous mudstones.The eocrinoid Guizhoueocrinus yui Zhao,Parsley et Peng,2007 was found in the upper part of this formation,and associated with brachiopods,hyolith molluscs,arthropods,and other taxa.The new fossil assemblage includes 8 genera and 9 species from different groups.The discovery of the Balang Fauna in Luojiatang,Cengong extends the geographical distribution of this fauna.Its well-preserved fossil assemblage provides important new material for study of community paleoecology and taphonomy in a critical window of the Early Cambrian.