Vaginella tricuspidata sp. nov., a new holoplanktonic mollusc from the Late Oligocene of SW France and Hungary

Amongst the holoplanktonic molluscan species from the Late Oligocene (Chattian) ’Marnes de St. Etienne-d’Orthe’ (southern Aquitaine Basin, France) occurs a peculiar species of Vaginella which is characterised by possessing three denticles at the dorsal apertural margin, a feature not yet described for any vaginellid species. This species was subsequently found to occur in Late Oligocene (Egerian) deposits in the Mucsony-136 borehole in Hungary (Borsod Basin), thus enabling interregional correlations; this attribute is the reason for the present description, in anticipation of a future treatment of the entire holoplanktonic molluscan fauna of the ‘Marnes de St. Etienne-d’Orthe’.