Late Piacenzian–Gelasian freshwater ostracods (Crustacea) from the L'Aquila Basin (central Apennines, Italy)

Abstract

Freshwater ostracod assemblages from San Demetrio Synthem (L'Aquila Basin, central Apennines, Italy), dating back to the late Piacenzian–Gelasian, are studied. Six genera and eight species are recognised, six of which are new: Caspiocypris amiterni Spadi & Gliozzi sp. nov., C. bosii Spadi & Gliozzi sp. nov., C. nicandroi Spadi & Gliozzi sp. nov., C. vestinae Spadi & Gliozzi sp. nov., Cypria bikeratia Spadi & Gliozzi sp. nov., and Ilyocypris ilae Spadi & Gliozzi sp. nov. Additionally, one fragmentary valve referred to Paralimnocythere cf. P. dictyonalis Medici, Ceci & Gliozzi, 2011, one valve ascribed to Amnicythere ex gr. stanchevae Krstić, 1975, one fragment tentatively identified as Limnocythere? sp. and four poorly preserved valves of Cypridoidea indet. were also recovered. The genus Caspiocypris is revised, and an emended diagnosis is provided. Comparisons are made with the most similar co-generic species occurring in the Neogene of Italy and the Paratethyan domain. The ostracod fauna of the San Demetrio Synthem shows the greatest affinity at the generic level with the Pontian (Messinian–Zanclean) ostracods of the Pannonic, Dacic and Euxinic Basins. To explain this affinity, two hypotheses are discussed: (1) passive dispersal of Paratethyan forms into the Italian Plio–Pleistocene palaeolakes; and (2) endemic evolution of several species in different Plio–Pleistocene palaeolakes from the Paratethyan-like late Messinian Lago-Mare ostracod fauna of the Palaeomediterranean area.

http://zoobank.org/urn:lsid:zoobank.org:pub:881D73C7-E62E-460A-A465-363DAE20A8D5

Keywords:

• Ostracoda
• taxonomy
• Piacenzian–Gelasian
• L'Aquila Basin
• Italy
• palaeobiogeography

Acknowledgements

We wish to thank the two referees, Dan Danielopol and Martin Gross, whose comments greatly improved the manuscript. Although this paper addresses an Italian ostracod assemblage, many comparisons have been made with Paratethyan taxa, which was possible through the help of several colleagues to whom we are deeply grateful for making material available: Tatiana Dmitrieva, Head of the Micropaleontology Laboratory of VNIGRI, St. Petersburg, Russia, and her staff, Lázló Kordos, Head of the Geological Museum of Budapest (Hungary), and Natalia Dykan of the National Academy of Science of Ukraine. We are grateful to Sergio Lo Mastro for the SEM pictures taken using a Philips XL30 Scanning Electron Microscope (LIME, Roma Tre University). Finally, we wish to thank Daniela Esu for the identification of the molluscs of the San Demetrio Synthem. This work was supported by a grant (2013) to Elsa Gliozzi from the Department of Science, University of Roma Tre.