Fossil chondrichthyan fishes: Mesozoic and Cenozoic chimaeroid fishes (Holocephali), worldwide; Triassic, Jurassic, Cretaceous and Palaeogene elasmobranchs (sharks, rays and skates) from the European Russia and former USSR; the stratigraphy of the Jurassic, Cretaceous and Palaeogene deposits of the Vorga region, European Russia; vital function's traces (coprolites) of fossil chondrichthyan fishes.