Ecological Features of Echinoderm Distribution in the Latorp and Volkhov Regional Stages of the Lower and Middle Ordovician of the Leningrad Region

The systematic composition and paleoecological distribution of echinoderms in the rocks of the Latorp and Volkhov regional stages of the Lower and Middle Ordovician of the Leningrad Region are reviewed. The basic types of soft-, firm-, and hardground echinoderm communities are reconstructed; the features of their formation and spatial and temporal variation are described.