陕西宁强地区早寒武世磷酸盐化Punctatus新材料  

NEW MATERIAL OF PHOSPHATIZED PUNCTATUS FROM LOWER CAMBRIAN IN NINGQIANG,SOUTH SHAANXI,CHINA

作　　者：刘云焕[1] 李勇[1] 邵铁全[1] 于波[1] 李圆圆[1] 张琬茜[1] 武春英[1] 李荣西[1] 

机构地区：[1]长安大学资源学院,西安710054

出　　处：《古生物学报》2006年第1期95-101,共7页Acta Palaeontologica Sinica

基　　金：国家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：描记在陕西南部宽川铺地区的灯影组宽川铺段的震旦-寒武系界线附近发现的具五辐对称特征磷酸盐化Punctatus新种———Punctatus triangulicostalissp.nov.(三角隆脊瘤点壳)。新种的锥体由5条放射状排列的锥脊组成,柱体由5纵列等间隔排列的三角隆脊组成,构成了完美的五辐对称生物体。同时描记的有PunctatusemeiensisHe,1980,新种与它的显著区别是具有与锥顶5条放射脊相对应的5纵列三角隆脊。新种呈三维立体保存,暗示生物体内部已具有一定的硬化程度,而锥体表层及柱状体表面的三角隆脊为磷酸盐化软组织。形态功能分析表明,Punctatus在分类上可能更接近于腔肠动物的水螅型。Punctatus triangulicostalis sp. nov. , is found from the Kuanehuanpu Member of the Dengying Formation near the Sinian-Cambrian boundary of Ningqiang County, Shaanxi Province. It is a kind of rare and perfect five-radial-eonelike metazoan. It differs from Punctatus emeiensis in having five lines composed of triangle-like transverse ridges that correspond to the pattern of a five-radial-symmetric organisim. The new species, three-dimensionally preserved in the rock layers implies that the organism has the ability to produce the skeleton representing an important innovation of the coelenterate trying to create hardparts since the extinction of the soft-bodied Ediacara fauna. Perhaps it represents an ancestor of the coelenterata with hardparts. DESCRIPTION OF NEW SPECIES Class ,Order and Family uncertain Genus Punctatus He, 1980 emend. Yue, 1984 Punctatus triangulicostalis sp. nov. （Text-fig. 2） Etymology ＂ trianguli＂ and ＂ costalis＂ , both from Latin, referring to the triangular and transverse ridges. Holotype No. k58 （Text-fig. 2）. Material A single well-preserved specimen. The specimen is deposited in the Resource Department of Chang＇an University. Diagnosis The features of the cone and cylinder of the specimen indicate that it is assignable to Punctatus. Its cross section is lens-shaped. According to its overall appearance, it can be subdivided into a cone and a cylinder （Text-fig. 2-a）. The bottom of cone is pentagonal and the distance between adjacent cone ridges is 450μm. The height of cone is 310μm. The cone ridge is undulant and the uneven cone surface subsided towards inside without ornaments on it （Text-fig. 2-c）. The base of the cone linked with 3--4 circular ridges. The distance between adjacent circular ridges is 75μm. The cylinder is characterized by each series （line） of triangle-like transverse ridges corresponding to a five-radial-symmetrical apex（Text-fig. 2-a）. The cylinder consists of five lines of triangle-like transverse ridges and five vertical furro

关 键 词：PUNCTATUS triangulicostalis sp.nov. 腔肠动物 灯影组宽川铺段 早寒武世陕西宁强 

分 类 号：Q915[天文地球—古生物学与地层学]