The Caenozoic Pickworthiidae of the European Atlantic Region (Mollusca, Gastropoda, Caenogastropoda)

Thirty-one species of Pickworthiidae from the Paleocene to Neogene of the European Atlantic region are recorded (including one Mediterranean Pliocene species). Seventeen species are described as new to science and two are unnamed. Four species are known from the Paleocene; two of them are new (Mareleptopoma? aliceae n. sp., Sansonia schnetleri n. sp.). Fourteen species are known from the Eocene. Among them, two are from the Lower Eocene, three from the Middle Eocene (of which two are new species: Gania gougeroti n. sp. and Gania fossaroides n. sp.), and ten from the Upper Eocene (of which eight are new species: Gania canhotensis n. sp., Gania granulosa n. sp., Gania laevigata n. sp., Gania priaboniana n. sp., Mareleptopoma orbum n. sp., Sansonia orthensis n. sp., Sansonia aturensis n. sp., Sansonia imperforata n. sp.). Two species are recognized from the Lower Oligocene (one unnamed) and six from the Upper Oligocene of which five are new species: Clatrosansonia praelapugyensis n. sp., Clatrosansonia luporadens n. sp., Gania marconensis n. sp., Gania peirahoradensis n. sp., Microliotia imperfecta n. sp. Three species are reported from the Lower Miocene including Astrosansonia micraster. This species was previously known only from the Middle Miocene of the Paratethys. Mareleptopoma lychoviense is recognized from the Lower Eocene to the Middle Miocene, with M. badenicum Janssen, 2004 as a synonym. It represents 74% of the recorded specimens. Higher diversity is reported in the Priabonian deposits where seven species occur in a single outcrop. The species have been predominantly collected from a restricted area of the Adour Basin (SW France) in a North Pyrenean Trough (Eocene) or in a paleo-canyon (Oligocene-Neogene). They are a good example of fossil distribution which is severely facies-dependent; the poor fossil records are probably an artefact due to the sparse habitat of this cryptic family. Finally, a species of Pickworthiidae is reported for the first time from the Miocene of the New World, Mareleptopoma toriferens Janssen, 2004 is transferred to the genus Gania, and the relocation of Mareleptopoma verdense Rolán & Rubio, 1999 to Chrystella is rebutted.