Phylogenetic study of the cephalopoda based on anatomical, embryological and molecular data

1)比较胚胎学研究在世界各地保存完好的材料的基础上，Tanabe和Shigeta利用扫描电子显微镜研究了各种菊科动物胚壳的胚壳特征，并与其他现存和化石的头足类动物的数据进行了比较。结果表明，菊科动物的胚壳特征与鹦鹉螺有很大的不同，但与鞘类动物的胚壳特征非常相似。Tanabe现在正在与Toba水族馆的Kimio Uchiyama先生一起研究水族馆中活着的鹦鹉螺壳的胚胎发育。这些研究的细节将发表在1995年出版的《菊科古生物学》(全会出版社)的一个章节中。比较解剖学研究1995年Tanabe和Mapes(1996.2)描述了俄克拉荷马州石炭纪菊科Cravenocera的颌骨和牙根，并讨论了其系统发育意义。3)系统发育问题为了了解菊科在头足类动物中的系统发生地位，Tanabe和Landman(美国自然历史博物馆，纽约)对5个分类单位的14个胚胎和解剖特征进行了分支分析。结果表明，头足类由鹦鹉螺总科和新头足目两个单系类群组成，而新头足目包括球头足目、单目总科和鞘总科。这一结果将发表在《诺维茨》杂志上1996.4)分子生物学研究远藤目前正在对著名的活化石鹦鹉螺进行分子系统研究。他还在分析保存在头足类硬组织中的生物分子，以获得分子进化的数据。

1) Comparative embryological studyOn the basis of well-preserved material from various localities throughout the world, Tanabe and Shigeta have investigated the embryonic shell features of the embryonic shells of various ammonoids using a scanning electron microsope, and the results were compared with data on other extant and fossil cephalopods. As a results, it was revealed that the embryonic shell features in ammonoids are quite different from those of nautilids but are quite similar to those of coleoids. Tanabe is now studying with Mr.Kimio Uchiyama of the Toba Aquarium on the embryonic shell development of living Nautilus in aquaria. Details of these studies will be published in a book chapter of "ammonoid Paleobiology" (Plenum Press) in 1996.2) Comparative anatomical studyTanabe and Mapes (1995) described the jaws and radula of a Carboniferous ammonoid Cravenoceras from Oklahoma and discussed its phylogenetic implications.3) Phylogenetic sutdyIn order to realize the phylogenetic position of the Ammonoidea within the Cephalopoda, Tanabe and Landman (American Museum of Natural History, New York) did a cladistic analysis of 14 embryonic and anatomical characters in five operational taxonomic units. As a result, it was realized the Cephalopoda consists of two monophyletic groups, the Nautiloidea and the Neocephalopoda, the latter includes the Sphaerorthocerida, Ammonoidea, and Coleoidea. This result will be published in Novitates in 1996.4) Molecular biological studyEndo is now doing research on the molecular systematic study on Nautilus, a well-known living fossil. He also is analyzing biomolecules preserved in cephalopod hard tissues to obtain data on molecular evolution.