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基于采自湖北长阳晚泥盆世黄家磴组(弗拉斯期)的新材料,对种子状结构武汉仙籽Sphinxiocarpon wuhanium(Li,Hilton and Hemsley)Wang,Xue and Prestianni进行比较形态学研究和几何形态统计分析。与模式产地(武汉米粮山珞珈群)的标本相比,长阳的标本显示出离体保存的单个种子状结构个体较大,具柄,囊状包被结构顶端收缩愈合,表面具纵向条纹,从柄延伸至顶端,而个体较小的种子状结构则聚成孢子叶球状。因此,仙籽属Sphinxiocarpon的个体发育早期阶段是一种孢子叶球状生殖形态,而发育后期通常脱落保存为单个的种子状结构,其母体植物可能是一种石松植物,但它与泥盆-石炭纪已知的异孢型石松类植物和前裸子植物都有较大差异,是一个很独特的分支。这些结果表明,在泥盆纪的前裸子植物-裸子植物谱系之外,同期其他植物类群(如石松植物)也演化出了与种子相似、具单一功能大孢子和包被结构的生殖器官,显示植物的生殖器官在不同类群中的趋同演化现象,它们可能以相似的方式(如减少大孢子数目、形成包被大孢子囊的结构等)来响应当时的环境胁迫。
Based on the new material collected from the Late Qingnian Huangjiaba Formation in Changyang, Hubei Province (Frasnian Period), comparative morphological studies were carried out on the seed-like structure of WuXi (Sphinxiocarpon wuhanium, Li, Hilton and Hemsley) Wang, Xue and Prestianni Geometrical statistic analysis. Compared with the specimens from the origin of the model (Wuhan rice grain Luojia group), the specimens of Changyang showed that the single seed-like structure preserved in vitro was larger and had a handle. The apical constriction of the capsule-shaped structure was healed and the surface had longitudinal stripes , Extending from the handle to the top, while the smaller seed-like structure of the individual aggregates into sporophytic leaves. Therefore, the early stage of individual development of Sphinxiocarpon is a globular reproductive form of sporophyte, which is usually exfoliated and preserved as a single seed-like structure in late development stage. The maternal plant may be a type of lycopodium, but it is associated with Devonian-Carboniferous Ji known heterophylla genus pine plants and former gymnosperms are quite different, is a very unique branch. These results indicate that in addition to the Devonian ancestral gymnosperm-gymnosperm lineage, other plant groups (eg, Pinus thunbergii) of the same period also evolved a reproductive organ similar to the seed with a single megaspore and a coated structure, showing Plant reproductive organs in different groups of the evolution of convergence, they may be in a similar way (such as reducing the number of megaspore, the formation of the structure of megaspore formation, etc.) to respond to the current environmental stress.