Saetaspongia sponges from the Cambrian (Stage 4) Balang Formation of Guizhou, China
Saetaspongia sponges from the Cambrian (Stage 4) Balang Formation of Guizhou, China
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DOI：
10.1017/jpa.2021.29
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发表时间：
2021-05
影响因子：
1.4
通讯作者：
Chen-Chen Ling-Chen;Jin Peng;Hui Zhang;Yifan Wang;Y. Shao;Quanyi Sun;Qiujun Wang
中科院分区：
文献类型：
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作者：
Chen-Chen Ling-Chen;Jin Peng;Hui Zhang;Yifan Wang;Y. Shao;Quanyi Sun;Qiujun Wang
抽象的。到目前为止，Saetaspongia还不能被自信地分配到任何级别的皇冠组。澄清其系统发育的位置需要新的信息提供更详细的研究以前描述的和/或新的材料。近年来，在中国贵州寒武纪（第四阶段）八郎生物群中发现了一些具有Saetaspongia典型骨架结构的海绵化石，包括S。jianhensis新种和S.参见S.密度。新分类群的特征如下：骨针是细的单轴体，倾向于松散或密集排列成羽状阵列;骨架主要由一个主要羽状束组成，具有不确定数量（可能是两个）的小羽状阵列;初级骨架偶尔散布着一些不规则取向的个体骨针。另一个标本由大的单轴体组成，具有羽状结构和覆盖的不规则粗单轴体，与先前描述的S。参见S.密度。通过结合以前的研究和本研究的信息，化石证据表明，羽状架构是Saetaspongia的一个重要特征诊断，并没有六角晶系为基础的骨针在这个属。来自巴朗生物群的新材料进一步支持了Saetaspongia具有原单轴类而不是hexactinellid亲和力的概念。化石证据表明Saetaspongia在早寒武世具有广泛的地理分布，该属的地层分布一直延伸到第4阶段。
Abstract. Saetaspongia so far cannot be confidently assigned to any class-level crown group. Clarifying its phylogenetic position requires new information provided by more detailed studies of previously described and/or new material. Some sponge fossils with the typical skeletal architecture of Saetaspongia have recently been recognized in the Cambrian (Stage 4) Balang Biota of Guizhou, China, including S. jianhensis new species and S. cf. S. densa. The new taxon is characterized by the following features: spicules are fine monaxons and are inclined to be loosely to densely arranged into plumose arrays; skeleton is composed primarily of one major plumose bundle, with an uncertain number (perhaps two) of small plumose arrays; and primary skeleton is occasionally interspersed with some irregularly oriented individual spicules. An additional specimen consisting of large monaxons, with plumose structures and overlying irregular coarse monaxons, closely fits the description and illustrations of previously described S. cf. S. densa. By combining information from previous studies and the present research, fossil evidence indicates that the plumose architecture is a critical feature diagnostic of Saetaspongia and that there are no hexactine-based spicules in this genus. The new material from the Balang Biota further supports the notion that Saetaspongia has a protomonaxonid rather than a hexactinellid affinity. Fossil evidence suggests that Saetaspongia had a wide biogeographic distribution during the early Cambrian and the stratigraphic distribution of this genus extends up to Stage 4.