摘要
华南寒武纪幸运期小壳化石生物群中已经报道了丰富多样的刺胞动物胚胎和幼年个体。以往的研究主要关注它们的解剖结构、个体发育、亲缘关系和演化意义,较少关注它们的种内变异。本文报道了来自陕南西乡县大河镇张家沟剖面寒武系幸运阶宽川铺组的刺胞动物意外秦钵水母(Qinscyphus necopinus)的幼年个体新材料。意外秦钵水母的围鞘上发育着细密的环纹和纵跨数个环纹的三角隆起。三角隆起每5个形成规则的1圈,均匀分布形成规则的5纵列,赋予秦钵水母五辐射对称的特征。新材料显示,在个别标本上同圈不同列的三角隆起可以错位生长,不形成规则的一圈。这些具有不规则排列三角隆起的个体可能为意外秦钵水母的种内变异个体,它们揭示了秦钵水母的水螅体在分泌建造围鞘的过程中具有各向不均衡性。
Abundant and diverse embryos and juveniles of probable cnidarian affinity have been reported from the Cambrian Fortunian small shelly fossil faunas in South China. Previous studies focus more on their anatomy, ontogeny,affinity, and evolutionary significance, but less on their intraspecific variations. Here, the new material of juveniles of cnidarian Qinscyphus necopinus is reported from the Cambrian Fortunian Kuanchuanpu Formation of the Zhangjiagou section at the Dahe Village, Xixiang County, southern Shaanxi Province. The periderm of Qinscyphus necopinus bears dense annuli and triangular thickenings each straddling on a few adjacent annuli. The triangular thickenings are arranged in circlet(s) of five, and are distributed evenly to form five longitudinal rows, thus imparting pentaradial symmetry on Qinscyphus necopinus. The new material demonstrates that the triangular thickenings in the same circlet may not strictly align in one circlet, but be slightly dislocated from each other. These juveniles with irregularly arranged triangular thickenings may represent individuals of Qinscyphus necopinus with intraspecific variations, demonstrating that there may be unevenness during the construction of periderms secreted by the scyphopolyps of Qinscyphus necopinus.
作者
张华侨
ZHANG Huaqiao(State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment,Chinese Academy of Sciences,Nanjing 210008,China)
出处
《微体古生物学报》
CSCD
北大核心
2022年第3期213-222,共10页
Acta Micropalaeontologica Sinica
基金
中国科学院南京地质古生物研究所现代古生物学和地层学国家重点实验室(20191104)支持。
