Calpionellid biostratigraphy of the upper tithonian-upper valanginian interval in Western Sicily (Italy)

A revision of the calpionellid bio-chronostratigraphy in Western Sicily ( Italy) was carried out, in order to update the taxonomy of this group, through the identification of some genera ( Borziella, Longicollaria, Chitinoidella, Dobeniella, Sturiella, Borzaiella and Praecalpionellites) and species ( Remaniella catalanoi POP, Remaniella duranddelgai POP, Remaniella colomi POP, Remaniella borzai POP, Remaniella filipescui POP) recorded for the first time in the area. The studied sections, belonging to the Trapanese and Saccense Domains ( Western Sicily), include at the base the upper portion of the Rosso Ammonitico Unit ( Upper Tithonian), followed by the Lattimusa Formation ( Lower Cretaceous). The quantitative and biostratigraphic analysis of the calpionellid assemblages allowed us to identify 13 assemblages and to define some important bioevents for the Upper Tithonian-Valangianian interval. The recorded calpionellid bioevents allowed us to recognize Zone/Subzone schema, which have been correlated with the bio-chronostratigraphy previously proposed for the Western Tethys.