New Data on the Genus Baltocrinus (Crinoidea, Iocrinidae) from the Ordovician of Leningrad Region

Calyxes articulated with stems, the characteristic pentagonal columnals of which have been known in the Baltic Ordovician since the time of Eichwald, were assigned by G.A. Stukalina in 1979 to the genus Baltocrinus in her form-taxonomy of crinoid columnals. They are described here, and their study suggested their placement in the family Iocrinidae of disparid crinoids, thereby placing the genus Baltocrinus in the natural classification. Two species were recognized based on calyxes; one species is new, and the other was successfully linked to the type species of a genus recognized based on the columnals.