New data on Scoliocystis (Echinodermata: Rhombifera) and related genera from the Ordovician of the Leningrad Region

New findings allow to refine and expand the taxonomy of Scoliocystis and related genera (class Rhombifera, family Echinoencrinitidae) from the Middle and Upper Ordovician of the Baltic-Ladoga Klint of the Leningrad Region. Similar evolutionary processes were traced within two groups of Baltic genera within the family Echinoencrinitidae.