陕南早寒武世具口部的磷酸盐化Punctatus及其胚胎化石

报道陕西南部灯影组宽川铺段地层中发现的Punctatus锥体标本、保留精美软组织特征的口部标本和可能的胚胎标本。对Punctatus软组织及整体形态功能研究表明,Punctatus在分类上可能更接近于腔肠动物的水螅型,代表初具原始触手的腔肠动物早期演化类型。在上万枚与Punctatus共生的球状化石中,发现若干枚可能的原肠期胚胎及胚胎发育晚期标本,在此基础上提出PunctatusemeiensisHe,1980花冠状口部可能经历的胚胎发育序列。

PRELIMINARY NOTE ON THE PHOSPHATIZED PUNCTATUS WITH MOUTHPARTS AND ITS EMBRYOS FROM LOWER CAMBRIAN IN NINGQIANG, SOUTH SHAANXI, CHINA

The appearance of coelenterates marks the real beginning of metazoan evolution. Therefore, it has a prominent position in the origin and evolutionary history of organisms, and is also a pivotal problem of evolutionary biology. Punctatus is a kind of cone-like extinct metazoan in deciphering the Cambrian explosion. Some research workers are inclined to regard Punctatus as coelenterate. Study on embryos and adult of Punctatus plays an important role in early evolution, classification, systematic development of metazoans. This field has became a focus of palaeozoology. In this paper we report a series of the Punctatus fossils with hard parts and finely preserved soft-tissue-mouthparts and fossilized metazoan embryos which were recovered from the Kuanchuanpu Member of the Dengying Formation in South Shaanxi, China in 2003.