CELLULAR STRUCTURE OF PERMINERALIZED BENNETTITALEAN PETIOLE AND STEM NEWLY FOUND

近年来在海相上野佐群（coniian - santonian）中发现了许多植物分类群。这些植物化石与各种海洋动物一起以过矿化碎屑的形式保存在钙质结核中。在上叶佐群中采集了一个贝尼蒂塔勒标本。它由一个花托组成，有许多可育的（有精的）和不育的（有精的）鳞片。虽然标本支离破碎，但其解剖特征保存完好。本研究提供了一种新的生殖器官的描述。由于其与Williamsoniaceae或Cycadeoidaceae及其近亲的亲缘关系尚不确定，我们暂时将本标本归为Bennetticarpus形属，并将其描述为B. yezoites sp. nov.并简要地与其他地区已知的Bennetticarpus yezoites分类群进行了比较。本标本与多种针叶树有亲缘关系，以红杉科为主。

Recently many plant-taxa have been described from the marine Upper Yezo Group (Coniacian-Santonian). These plant fossils are preserved as permineralized debris in calcareous nodules together with various marine animals. A single bennettitalean specimen was collected from the Upper Yezo Group. It consists of a receptacle, with numerous fertile (seminiferous) and sterile (interseminal) scales. Although the specimen is fragmented, its anatomical features are well preserved. This study provides a description of a new reproductive organ belonging to Bennettitales. As its affinity to Williamsoniaceae or Cycadeoidaceae and their allies is uncertain, we provisionally place our specimen in the form-genus Bennetticarpus and describe B. yezoites sp. nov.Comparison of Bennetticarpus yezoites with known bennettitalean taxa in other regions is given briefly.The present specimen is in association with various conifers, mainly with Taxodiaceae.