The article describes examples of attachment of bivalves to the surfaces of skeletons of Late Cretaceous hexatinellid marine sponges. Attachment is associated with the adaptation of mollusks to living conditions in mobile laminar streams of bottom water masses carrying nutrient suspension, carbonate material and terrigenous components. The bottom population is represented mainly by marine sponges, hexatinellides, as well as bivalves adapted to the active dynamics of bottom waters.
