Tanousia subovata (Settepassi) (Hydrobiidae), a Middle Pleistocene correlation element for the central-southern Italian lacustrine basins.

Rich assemblages of non–marine molluscs are recorded from the middle Pleistocene fluvio–lacustrine sediments of several Central–Southern Italian intramontane basins. By a malacological point of view the best investigated basins are: the Liri Valley (Latium), Vallo di Diano (Southern Campania), Noce river (Basilicata) and Mercure (Basilicata). Highly diversified freshwater molluscan assemblages of gastropods and bivalves, and a low degree of endemism characterize these basins. The endemic, extinct freshwater hydrobioid species, Tanousia subovata (Settepassi) is one of the most frequent taxon, occurring mainly in calcareous sands and silts or in marly clays. The age of the malacological assemblages containing T. subovata is constrained between about 0.8 Ma and 0.2 Ma. Then T. subovata, endemic of central–southern Italian intramontane basins, represents a good tool for the correlation of middle Pleistocene non–marine deposits

Variation in shell morphology in the fossil freshwater gastropod Tanousia subovata (SETTEPASSI 1965) from the Mercure Basin (Middle Pleistocene, southern Italy): Distinct taxa or ecophenotypic variation? (Gastropoda Prosobranchia: Hydrobiidae)

The study of the shell plasticity of the extinct Hydrobiidae Tanousia subovata (SETTEPASSI 1965) resulted in a better understanding of the relationships between the shape of the organisms and the environment that influenced their life. Three populations, from distinct sections of the lacustrine Middle Pleistocene Mercure Basin (Basilicata-Calabria, southern Italy), have been investigated, using a landmark-based geometric morphometric analysis to quantify the morphological variability. Morphometric data and data coming from independent proxies (such as lithology and other fossils), already published on the studied basin, have been taken into account. Results have been interpreted to discriminate between internal and external factors influencing the shape of the shell. The geometric morphometric method proved useful to reveal some morphological variations between the three populations, which, following the comparisons with palaeoenvironmental data and with the literature appear to result from ecological or maybe chronological factors rather than indicating distinct species

Palaeoenvironmental reconstruction of late Quaternary foraminifera and molluscs from the ENEA borehole (Versilian plain, Tuscany, Italy)

Foraminifera and molluscs from the 90 m deep ENEA borehole (Versilian plain, central Italy) were studied for paleoenvironmental purposes. Palaeontological analyses, integrated with U/Th and radiocarbon data, helped to recognize late Quaternary sea-level changes and supplied results on tectonic mobility of the area. The study highlighted four sedimentary phases. The first phase consists of a shore environment attributed to MIS 7.1. A hiatus corresponding to MIS 6 is hypothesized at the top of this interval. Recognition of the paleo-shoreline of MIS 7.1 at - 72.8. m signifies a vertical displacement due to the extensional tectonics of the Apennine orogenesis. The second phase consists of a transgressive succession with evidence of warm temperatures, which was interpreted as part of the transgression leading to the MIS 5.5 highstand. The third phase includes sub-aerial and lacustrine deposits. Radiocarbon dates and palaeoecological reconstruction led us to attribute this interval to MIS 4, MIS 3 and MIS 2. The fourth phase begins with a lagoon environment attributable to Holocene sea-level rise and ends with marsh episodes, signifying the progradation of the alluvial plain. This reconstruction confirms the hypothesis of tectonic stability for the Versilian area during the Holocene. © 2010 University of Washington