华南地区湖南省芙蓉统(上寒武统)的古蠕虫骨片:个体生长对表皮骨片形态的影响

报道最近发现的华南地区湖南省芙蓉统(上寒武统)三维保存的古蠕虫骨片碎片。描述两个新的形态属和两个新的形态种: Hunanoscolex campus 新属新种和Ornatoscolex hunanensis新属新种。大部分标本属于幼体阶段。Hunanoscolex campus体节宽度的巨大差异显示其处于生长发育阶段, 因此可以对个体生长对表皮骨片形态的影响进行研究。虫体生长主要依靠增加单个体节中骨片的数量。位于同一排中的大骨板排列变得疏松。新增加的小骨板和微骨板大小和纹饰基本不变, 但大骨板的纹饰可能存在变化。这些观察结果有助于更好地理解古蠕虫骨片的种内差异, 从而可能提高形态种属分类的准确性。

Furongian (Late Cambrian) Palaeoscolecid Cuticles from Hunan Province, South China: the Growth Impact on the Worm Cuticle

Newly recovered palaeoscolecid cuticle fragments in 3-D preservation from the Furongian (upper Cambrian) of Hunan Province, South China are reported. Two form new genera and two form new species, Hunanoscolex campus gen. et sp. nov. and Ornatoscolex hunanensis gen. et sp. nov. are described. Most of the specimens are juvenile individuals. The great variation of annulus width in Hunanoscolex campus indicates growth of the worm, which allows us to examine the growth impact on the worm cuticle. The worm grows by adding more sclerites to each annulus. The spacing of plates in the same row gets looser. The new microplates and platelets remain constant in size and ornamentation but the ornamentation of plate may change. These observations give better understanding of the intraspecific variation of the worm cuticle, and may enhance the taxonomy accuracy of palaeoscolecid cuticle fragments.