Ricciisporites属的分布及其地层学意义

概述了Ｒｉｃｃｉｉｓｐｏｒｉｔｅｓ属的基本形态、分类和时空分布。由于形态特殊，层位稳定，一般丰度较高，故此属为北半球中生代最重要分子之一，主要出现于瑞替阶和下里阿斯阶，在中国仅见于华南上三叠统，是划分三叠系／侏罗系的标志分子。其母体植物可能生长于距渴湖、海湾岸边较近的生境。

ON DISTRIBUTION OF Ricciisporites IN CHINA AND ITS STRATIGRAPHICAL SIGNIFICANCE

Under review is the general morphology of Ricciisporites with its leading species R. tuberculatus Lundblad and R. umbonatus Felix and Burbridge. Most forms so far recorded by the Chinese palynologists may be assigned to these two species.Due to its peculiar morphology,relatively stable vertical range and abundant content in most cases,Ricciisporites is one of the most important palynomorphys in Mesozoic strata.On a global scale, this genus is mainly distributed within the Rhaetic and lower Liassic Stages of the Northern Hemisphere.In China,it is mainly concentrated in the Noric-Rhaetic Stage of Late Triassic,with only occassional occurrence in the Carnic Stage,but no record has yet been known in Liassic.Therefore,Ricciisporites is one of the index forms for the division of Upper Triassic and Lower Jurassic. Since it is usually found in the deposits of littoral and lagoonal factes,its parent plants might have grown in sites not far from these environments.