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Morphologic and crystallographic study on the skeletal homology of crinoids (Echinodermata)

海百合（棘皮动物）骨骼同源性的形态学和晶体学研究

基本信息

批准号：
10440145
负责人：
OJI Tatsuo
金额：
$ 4.48万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10440145/
关键词：
phylogeny development Echinodermata Crinoidea development phylogeny skeleton Articulata ウミユリ相同性

项目摘要

In this year I conducted two major researches in relation to this grant ; 1) SEM observation of the skeletal growth during developmental stages of three species of modern comatulids, 2) Fossil evidence about the presumable rapid evolutionary changes of the subclass Articulata across the Paleozoic-Mesozoic boundary.Specimens of Oxycomanthus japonicus were collected from Koajiro Cove of Sagami Bay, and their spawning and development after fertilization were monitored. Also, pentacrinoid stage of two other comatulids, Antedon bifida and Decametra tigrina, were observed. The results include :1. Anal plate was detected in pentacrioids of Oxycomanthus j. for the first time. This is the first report of anal plate from the suborder Oligophreatina. The anal plate were widely observed in the three subclasses of the Paleozoic, but this discovery from some articulata implies that its existence cannot be a good character of the articulata.2. All three comatulids share synarthrial articulation in the pentacrinoid stalk. The present data, combined with previous data about pentacrinoids of various articulates, suggest that existence of synarthry in the pentacrinoid stalk would be a good synapomorphic character of the Articulata.3. The number of columnals probably increases during the cystoid stage, but it is almost constant and longitudinal grow of each columnals are observed during the pentacrinoid stage.Also data about Late Permian-Early Triassic articulates, both specimens (NE Japan, Nevada) and data from reference papers, shows the following :4. Across the boundary, the number of ligamentary articulations in the arms suddenly decreased, and articulates have acquired the ability of arm autotomy at ligamentary acticulations. This evolutionary novelty must deeply be related to the suceess of the Articulata.

在这一年里，我进行了两项与这项赠款有关的主要研究; 1）现代三种鞭毛虫骨骼发育过程的扫描电镜观察; 2）节肢动物亚类跨越古生代-中生代界线的快速演化的化石证据。并监测其产卵和受精后的发育情况。此外，还观察到另外两种comatulids，Antedon bifida和Decametra tigrina的pentacrinoid阶段。研究结果包括：1.首次在尖果草属植物的五芒星中发现肛板。这是首次报道的肛板化石。肛板在古生代的三个亚类中广泛存在，但在某些有节类中的发现，意味着它的存在并不是有节类的一个好特征.所有三个comatulids共享synarthral关节在pentacrinoid柄。结合以往关于不同关节类五角体的研究结果，我们认为，在五角体柄中存在联肢是关节类的一个良好的突触形态特征.柱状体的数量在囊状阶段可能有所增加，但在五轴类阶段几乎不变，并且每个柱状体的纵向生长都被观察到。关于晚二叠世-早三叠世关节的数据，两个标本（日本东北部，内华达州）和参考文献的数据显示了以下几点：4.越过边界，手臂中的韧带关节的数量突然减少，并且关节已经获得了在韧带活动处手臂自切的能力。这种进化上的新奇一定与关节动物的成功有着深刻的联系。