Evolution of Rudist revealed by their shell micro sturucture

双壳类是生活在中生代，特别是侏罗纪和白垩纪之间的一类贝壳形态特殊的双壳类，主要为无柄双壳类。这群人在那段时间享受着他们的繁荣。它们的化石丰富地产于碳酸盐台地环境中，是有机建造物的重要元素。该群在晚侏罗世以一个科的形式出现，到白垩纪分化为6科100属。本文研究了该群的特殊形态和特殊的贝壳结构。在德国、奥地利、斯洛文尼亚以及意大利北部也参观和考察了鲁德派化石的几个重要地点。最后，由Cestari，R.和Sartorio，D.(Agip，S.p.A.，S.Donanto Milanes出版)撰写的关于这一主题的经典教科书《陆上陆域的粗略和相》被翻译成日语，以促进日本古生物学家对这一主题的研究。

Rudists are a group of mainly sessile bivalves with peculiar shell forms, which lived in the Mesozoic Era arid especially between Jurassic and Cretaceous Periods in so called Thethysan Region. The group enjoyed their prosperity during the time. Their fossils occur abundantly from carbonate plat-form environments, and were an important element as organic builder. The group appeared as one family in the late Jurassic, then during the Cretaceous Period it diversified into 6 families including 100 genera.In the present study, the peculiar morphology of the group as well as peculiar shell structure was investigated.To do so material in Vienna University as well as in Natural History Museum, Vienna, Austria was examined. Also several important localities of the Rudist fossils was visited and examined in Germany, Austria, and Slovenia as well as northern Italy.Finally a classic Text book on this theme, "Rudists and facies of the Periadriatic Domain" written by Cestari, R. and Sartorio, D. (1995) (published by Agip, S.p.A., S. Donanto Milanese) was translated into Japanese to stimulate the study on this topic by Japanese paleontologists.