Abstract

A crown of Streptoiocrinus gen. nov., with its articulated stem, the columnals of which have long been known in the Billingen and Volkhov regional stages (Floian and Dapingian stages) of the Leningrad Region and Estonia are described. A detailed study of the crown and stem morphology showed that the new genus belongs to the disparid crinoid superfamily Ioсrinacea. This genus is the first mass crinoid invader into the Ordovician Baltic paleobasin. The fluctuating asymmetry in the manifestation of the pentaradial symmetry of the stem columnals is described.

中文翻译：

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链球菌 十一月 列宁格勒地区的下奥陶纪和中奥陶纪的（Disparida，Crinoidea）和径向对称的波动不对称

摘要

冠Streptoiocrinus根。十一月，用其铰接的茎，描述了列宁格勒地区和爱沙尼亚的Billingen和Volkhov区域阶段（弗洛伊安和大坪时期）早已知道其柱状结构。对冠和茎形态的详细研究表明，该新属属于不同的海百合类超家族。该属是第一次进入奥陶纪波罗的海古生物的大规模海百合。描述了茎柱五边形对称性表现的波动不对称性。