First record of ammonites in the Bonarelli Level (uppermost Cenomanian) of the Umbria-Marche Succession

Ugo Donatelli(*), Mario Tramontana(*) & F. Venturi(**)
(*) Dipartimento di Scienze Geologiche, Tecnologie Chimiche e Ambientali (DiGeoTeCa), Università degli Studi di Urbino «Carlo Bo», Campus Scientifico, Località Crocicchia - 61029 Urbino (PU), Italy. E-mail: mario.tramontana@uniurb.it (**) Dipartimento di Scienze della Terra, Piazza dell'Università -06123 Perugia (PG), Italy.

The presence of ammonites in the Bonarelli Level (uppermost Cenomanian) of the Umbria-Marche Succession is reported here for the first time. The horizon studied has been recognised near Serra S. Abbondio, on the external limb of the Mt. Catria anticline, where the upper part of the Scaglia Bianca Formation and the interbedded Bonarelli Level crop out. An ammonite, preserved as a bidimensional trace, has been found within one black shale bed which characterizes the level. The lack of diagnostic elements does not allow a precise taxonomic identification. However, based on the morphologic features, this form can be tentatively ascribed to the suborder Lytoceratina.

Bonarelli Level, Ammonites, Black Shales, Scaglia Bianca Fm, Umbria-Marche Succession.