Systematics and biostratigraphy of the Ostracoda of the Plio-Pleistocene Monte S. Nicola section (Gela, Sicily)

The ostracod assemblages of the Plio-Pleistocene section of Monte S. Nicola (Gela, Sicily) are studied. The section, sampled at 2 m intervals, yelded 113 species, belonging to 46 genera, ten of which are left in open nomenclature due to scarce or badly preserved material. The following species: Bairdoppilata profunda sp. nov., Occultocythereis culter sp. nov. and Propontocypris dromas sp. nov., are described as new. Most of the species are treated taxonomically, with data on their stratigraphical distribution and palaeoecology. Some species which were imperfectly described are better illustrated. The qualitative distribution of the species through the section, shows a high number of appearance and disappearences. First appearances of species are staggered throughout the section; this and the limited stratigraphical ranges of certain species indicate the biostratigraphical potential of the Ostracoda. In particular, the genus Krithe is of high diversity and numerous species appear restricted to well defined and frequently short intervals. Many of the Krithe species have never been recorded from the Atlantic, suggesting the possibility that the Mediterranean Basin, due to its peculiar character, may have acted as a laboratory of evolution especially of this genus.