本文描述了云南寒武纪早期澄江生物群中原始单轴针海绵化石一新属种——群体小卵海绵Ovulispongia multa gen. et sp. nov.。群体小卵海绵为小型薄壁海绵,整体呈卵形,骨骼双层,由四个方向的单轴骨针穿插成网状,左倾方向和右倾方向骨针...本文描述了云南寒武纪早期澄江生物群中原始单轴针海绵化石一新属种——群体小卵海绵Ovulispongia multa gen. et sp. nov.。群体小卵海绵为小型薄壁海绵,整体呈卵形,骨骼双层,由四个方向的单轴骨针穿插成网状,左倾方向和右倾方向骨针与水平骨针和纵向骨针斜交呈45度角;骨针之间无叠接;海绵体无口须和根须。群体小卵海绵在外部形态和骨架类型上与其他的原始单轴针海绵存在明显差异,其半紧密型骨架处于无规则排列的鬃毛海绵骨架和规则排列的细丝海绵骨架之间。另外新材料显示在海底固着取食的生态环境中,新属种用高密度的个体分布来获得竞争优势。群体小卵海绵独特的过渡形态的骨架结构和高密度生态分布为研究古生代原始单轴针海绵的骨架演化与生态空间扩张之间的关系提供了线索,也为研究寒武纪早期海绵动物的起源和多样化提供新的化石材料。展开更多
Here is currently little consensus on the branching order and phyletic status of the oldest metazoan groups, but sponges are widely believed to be the earliestbranching living metazoans. Porifera are thought to have d...Here is currently little consensus on the branching order and phyletic status of the oldest metazoan groups, but sponges are widely believed to be the earliestbranching living metazoans. Porifera are thought to have diverged before the emergence of developmental characters typical of Eumetazoa, such as well-defined symmetry; extant sponges show radial symmetry of indeterminate high order, or none, combined with polarisation along the axis. In contrast, other early-branching phyla include bilateral and tetraradial(Cnidaria) and biradial(Ctenophora) symmetry, or none(Placozoa). A variety of prismatic early fossil sponges had shown here where the shared symmetry has been overlooked, and also describe structural tetraradial symmetry in Cambrian sponges from South China. Based on this study, this symmetry is likely to have been a primitive feature of sponges, and that the earliest-known fossil sponges were highly organised, cellularly integrated individuals whose body form was under strict genetic control.展开更多
文摘本文描述了云南寒武纪早期澄江生物群中原始单轴针海绵化石一新属种——群体小卵海绵Ovulispongia multa gen. et sp. nov.。群体小卵海绵为小型薄壁海绵,整体呈卵形,骨骼双层,由四个方向的单轴骨针穿插成网状,左倾方向和右倾方向骨针与水平骨针和纵向骨针斜交呈45度角;骨针之间无叠接;海绵体无口须和根须。群体小卵海绵在外部形态和骨架类型上与其他的原始单轴针海绵存在明显差异,其半紧密型骨架处于无规则排列的鬃毛海绵骨架和规则排列的细丝海绵骨架之间。另外新材料显示在海底固着取食的生态环境中,新属种用高密度的个体分布来获得竞争优势。群体小卵海绵独特的过渡形态的骨架结构和高密度生态分布为研究古生代原始单轴针海绵的骨架演化与生态空间扩张之间的关系提供了线索,也为研究寒武纪早期海绵动物的起源和多样化提供新的化石材料。
基金supported by the Chinese Academy ofSciences(KZZD-EW-02)the Project-Oriented Hundred TalentsProgram of the Chinese Academy of Sciences(KZCX2-YW-BR-23)the National Science Foundation of China Research Fellowshipfor International Young Scientists(41150110152)
文摘Here is currently little consensus on the branching order and phyletic status of the oldest metazoan groups, but sponges are widely believed to be the earliestbranching living metazoans. Porifera are thought to have diverged before the emergence of developmental characters typical of Eumetazoa, such as well-defined symmetry; extant sponges show radial symmetry of indeterminate high order, or none, combined with polarisation along the axis. In contrast, other early-branching phyla include bilateral and tetraradial(Cnidaria) and biradial(Ctenophora) symmetry, or none(Placozoa). A variety of prismatic early fossil sponges had shown here where the shared symmetry has been overlooked, and also describe structural tetraradial symmetry in Cambrian sponges from South China. Based on this study, this symmetry is likely to have been a primitive feature of sponges, and that the earliest-known fossil sponges were highly organised, cellularly integrated individuals whose body form was under strict genetic control.
