Notes on the systematics, morphology and biostratigraphy of fossil holoplanktonic Mollusca, 6. Biostratigraphical interpretation of an assemblage from Poggio Musenna (Sicily, Italy) in comparison to northern Italian and Maltese localities

Miocene holoplanktonic Mollusca from the Tellaro Formation at Poggio Musenna (SE Sicily, Italy) are compared with assemblages from the Blue Clay Formation in the Maltese Archipelago and from Tetti Borelli (N. Italy, province of Asti). Similarities in benthic assemblages of the Tellaro and Blue Clay formations are merely the result of identical depositional environments and do not indicate the same age. The Tellaro Formation was analysed for nannoplankton and found to belong to zone NN10 (Middle Tortonian). The S. Agata Fossili Formation Montaldo Member) of Tetti Borelli may be dated as Early to Middle Tortonian, as indicated by the nannoplankton and holoplanktonic molluscan assemblages. In contrast, the Maltese Blue Clay Formation is of Serravallian age. In Malta pteropods of Tortonian age are found reworked in the Messinian Green Sand Formation.