陕南早寒武世具口部的磷酸盐化Punctatus及其胚胎化石  

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

作　　者：刘云焕[1] 李勇[1] 邵铁全[1] 朱志新[2] 于波[1] 王焯[1] 张琬茜[1] 李荣西[1] 

机构地区：[1]长安大学资源学院,西安710054 [2]中国地质科学院地质研究所,北京100037

出　　处：《古生物学报》2006年第2期182-194,共13页Acta Palaeontologica Sinica

基　　金：教育部重点科研项目(No.104176);国家自然科学基金(No.40173005)资助课题。

摘　　要：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。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 evolu-tionary 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. By studying on soft tissues and functional morphology, there is evidence to show that Punctatus resembles coelenterates polyps in systematic classification. The Punctantus emeiensis with complete mouthparts can be divided into two morphological types： （1） The oval corolliform mouthpart with ten ＂flower petals＂ （Text-fig. 2） ： the cylinder connected with the complete elliptical corolliform mouthpart is 3 mm in length. There are some thick transverse ridges and some closely spaced parallel vertical lines between the ridges, the width of the ridges being about 80--100 μm and the space in between being 500 /μm, the width of the vertical lines being 8--10 μm. The elliptical corolliform mouthpart is completely preserved, the elongated axis is 1.8 ram,the shortened axis 1.25 mm, and is made up of the drape piamater convergent from the inside and outside circle towards the center （Text- fig. 2-b,c,d）. The piamater has the close parallel strialongitudinalis （Text-fig. 2-c, d, f） and the 10 double-layered folds showing V-shaped outline and taking on radi- ating and circumgyrating into two circles（Text-fig. 2-b, d）. The petal has a function of primitive tentacle

关 键 词：PUNCTATUS 口部构造 腔肠动物 胚胎化石 梅树村期 灯影组宽川铺段 陕南 

分 类 号：Q915[天文地球—古生物学与地层学]