Bithynia abbatiae n. sp (Caenogastropoda) from the Lower Pliocene of the Pesa River Valley (Tuscany, central Italy) and palaeobiogeographical remarks

A new extinct freshwater gastropod species, Bithynia abbatiae n. sp., representative of the Family Bithyniidae (Caenogastropoda, Truncatelloidea), is described. It was recorded from lacustrine-palustrine layers of the stratigraphical section Sambuca Nord, near the Sambuca village in the Pesa Valley, sub-basin of the adjacent Valdelsa Basin (Tuscany, central Italy). These deposits are rich in non-marine molluscs and ostracods. Stratigraphical correlations and palaeontological data (mammals and microfossils) of the Valdelsa Basin indicate an Early Pliocene age for the analysed deposits, supported also by the eastern affinity of the recorded molluscs and ostracods.