广西靖西寒武系芙蓉统始海百合一新属

A NEW EOCRINOID GENUS FROM THE UPPER CAMBRIAN OF GUANGXI,SOUTH CHINA

描述了发现于广西靖西果乐寒武系芙蓉统果乐组的始海百合化石,确定其为始海百合纲Ridersiidae科一新属:Jingxieocrinus gen.nov.。新属特征如下:个体较小,锥形萼。萼板15块,排列规则,其中五边形底板5块,六边形侧板5块,五边形辐板5块,无萼孔及缝孔。茎长,始端粗,向末端迅速变尖。始端茎板矮,大小茎板交互重叠,向末端茎板变高,大小茎板趋于一致。腕羽5枝,细长不分叉,双列小板,生于口缘辐板相间处。偶见盖板,横椭圆形,上覆放射状纹饰。模式种Jingxieocrinus guoleensis gen.et.sp.nov.的茎细且长,末端变尖,没有固着器,可能以茎末端附着于其它物体上营假浮游或寄生漂游生活。

The eocrinoid specimens collected from the Guole Formation of the Furongian （Late Cambrian） in the Guole area of Jingxi, Guangxi, are described here; one new genus and species Jingxieocrinusguoleensis gen. et. sp. nov. is named based on the new materials. The new genus is defined by small-sized, cone-shaped theca which tapers gradually. Thecal wall made up of fifteen well-organized plates, including five pentagonal basals, five hexagonal laterals and five pentagonal radials. No thecal pores or sutural pores have been observed. Stalk long, of low and alternating of big and small disc-shaped ossicles proximally and tapering strongly, and then of relatively uniform barrel- shaped ossicles. Five slender brachioles with biserial ossicles located at the edge of oral surface among the radials. Oval cover plates with radial ornaments were rarely preserved. Jingxieocrinus guoleensis gen. et. sp. nov. developed a long slender stalk with a pointed distal and no holdfast, may have floated in the seawater with the stalk attached to other objects.