皖南早寒武世荷塘组海绵骨针化石

SPONGE SPICULES IN EARLY CAMBRIAN HETANG FORMATION, XIUNING, SOUTHERN ANHUI

本文报道皖南休宁县早寒武世荷塘组黑色页岩中产出的海绵骨针化石组合 ,这些海绵骨针化石具有较高的丰度和分异度 ,它们以二轴四射针、T型针、三轴六射针和三轴五射针为主。骨针形态完整 ,并保存了内部轴丝、轴管以及同心圈层等微细构造。黄铁矿化在化石的保存中起了重要的作用 ,化石产出的时代可能为梅树村阶至筇竹寺阶 (Tomm otian- Atdabanian) ,这个化石组合证实了海绵动物在早寒武世已开始迅速分异。

We report a sponge spicule assemblage from the Lower Cambrian black shales of the Hetang Formation at Xiuning in Anhui Province, South China. Based on morphological differences, the spicules can be divided into 4 types including monaxons, biaxons, triaxons and tetraxons. In thin sections and macerated specimens, axial canal (or filament) and concentric stratification within the sponge spicules can be observed. Pyritization occurred commonly in spicules, which could play an important role for the preservation of the spicules. The Hetang sponge spicules indicate that the hexactinellids and demosponges evolved no later than the Meishucunian-Qiongzhusian (Tommotian - Atdabanian) time.