Acta Scientiarum Naturalium Universitatis Pekinensis

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Middle Cambrian Highly Modified Sponge Spicules from Western Hunan,South China

CHEN Fang, DONG Xiping   

  1. School of Earth and Space Sciences, Peking University, Beijing 100871;
  • Received:2007-11-29 Online:2008-11-20 Published:2008-11-20



  1. 北京大学地球与空间科学学院,北京100871;

Abstract: The newly recovered assemblages of disarticulated sponge spicules are reported, occurring in Middle Cambrian carbonates from Wangcun section, western Hunan, South China. The most abundant kinds of spicules include stauractins, tauactins, triaxon pentactins and pentaxon pentactins. Axial canals can be observed on these well preserved specimens. A highly modified form of pentaxon pentacins is recognized as a new genus-Speciosuspongia, with two new species: Speciosuspongia hunanensis and Speciosuspongia wangcunensis. Speciosuspongia is a bilateral symmetrical siliceous pentaxon pentactin. One ray is bulky and in the symmetrical plane, the other four rays are assorted as two pairs. The bulky ray of Speciosuspongia hunanensis is deformed to a plate, which is interpreted as an important intermediate character between highly modified sponge spicules of Early and Late Cambrian.

Key words: Middle Cambrian, sponge spicules, Hunan

摘要: 报道湖南西部王村剖面中寒武世灰岩中产出的海绵骨针化石组合。这些海绵骨针化石以二轴四射针、T型针、三轴五射针和五轴五射针为主。骨针形态完整,保存了轴管构造。描述了罕见的,形态变异性极大的(highly modified)一个新属眩目海绵属Speciosuspongia,两个新种湖南眩目海绵Speciosuspongia hunanensis和王村眩目海绵Speciosuspongia wangcunensis。眩目海绵的主要特点为:两侧对称,硅质,五轴五射,中轴与一条针射重合,另外4条针射分为两对,与中轴重合的针射比其他4条针射粗大。其中,湖南眩目海绵Speciosuspongia hunanensis前射基部或整体膨大成骨板,这一变异体现了海绵骨针的典型变异形态自早寒武世向晚寒武世的过渡,具有重要的演化意义。

关键词: 中寒武世, 海绵骨针, 湖南

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