Albian dinoflagellates from the Umbria-Marche Basin (Italy): Proposal for biozonation of of the Tethyan domain

The Albian Stage in the Umbria-Marche Basin (central Italy) is characterize d by pelagic deposits, well-defined stratigraphically by planktic foraminif eral and calcareous nannofossil events. The detailed study of dinocysts has led to the identification of 82 taxa and a zonation composed of five main dinoflagellate zones has been proposed. The Hapsocysta peridictya Zone mark s the Aptian/Albian boundary and the base of the lower Albian. The Tehamadi nium coummia-Systematophora cretacea and Litosphaeridium arundum zones resp ectively characterize the lower and upper parts of the middle Albian. The T ehamadinium mazaganense Zone marks the upper Albian and the Litosphaeridium siphoniphorum-Hapsocysta dictyota Zone, the uppermost Albian. These differ ent dinocyst zones, stratigraphically correlated with the standard planktic foraminiferal and nannofossil events established in the same basin, have b een compared with the standard Tethyan ammonite scale. The proposed biozona tion fills a gap in the dinocyst zonation of the Tethyan Realm. (C) 2001 Ac ademic Press.