сеноманский ярус On the Stratigraphic Significance of Elasmobranchs (Chondrichtyes, Elasmobranchii)) in the Cenomanian of the Volga River Basin (Right Bank) Authors: Biryukov A. В. The paper analyzes the stratigraphic distribution of elasmobranchs in the deposits of the Melovatka Formation (Cenomanian) from the right bank of the Volga (part of the Penza, Saratov and Volgograd regions).