Nummulite biostratigraphy at the Middle/Upper Eocene boundary in the northern Mediterranean area

Some larger foraminifera assemblages (mostly nummulitids) near the Middle/Upper Eocene boundary have been investigated. Sections of the Veneto area (Berici and Lessini Mts., northern Italy) were studied and compared with others of the same age from Spain (Ebro basin) and Romania (Cluj-Napoca). In the Veneto area the results allow to split the upper Middle Eocene Nummulites brongniarti Zone into two biozones: a lower N. lyelli Zone and an upper N. biedai Zone. The N. aff. fabianii Zone is here renamed N. variolarius/incrassatus Zone. This subdivision can also be recognized in Spain and Romania.According to the current conceptions, the base of the Priabonian (= Upper Eocene) could correspond either to the base of the N. fabianii s.s. Zone or to the base of the N. variolarius/incrassatus Zone. Anyway, the Mossano succession could be a potential Global Stratotype Section and Point for the base of the Priabonian.