The upper Miocene gastropods of northwestern France, 1. Patellogastropoda and Vetigastropoda

Seventy-six species are recorded of which 26 are new to science: Diodora sancticlementensis nov. sp., Sinezona geigeri nov. sp., Anatoma redoniana nov. sp., Clanculus (Clanculus) brebioni nov. sp., Clanculus (Clanculopsis) sancticlementensis nov. sp., Clanculus (Clanculopsis) umbilicovadus nov. sp., Jujubinus coronatus nov. sp., Jujubinus redoniensis nov. sp., Jujubinus sceauxensis nov. sp., Gibbula brebioni nov. sp., Gibbula clanculiforma nov. sp., Gibbula conicomagus nov. sp., Gibbula marianae nov. sp., Phorcus gallicophorcus nov. sp., Calliostoma gibbuliforme nov. sp., Calliostoma lamellatum nov. sp., Calliostoma michaeli nov. sp., Calliostoma microgemmatum nov. sp., Calliostoma quaggaoides nov. sp., Calliostoma presselierense nov. sp., Calliostoma spinosum nov. sp., Calliostoma verrucosum nov. sp., Thysanodonta chauvereauensis nov. sp., Pareuchelus dautzenbergi nov. sp., Dikoleps insulsa nov. sp., Lodderena redferni nov. sp., Parviturbo rubioi nov. sp., Pseudorbis beugnonensis nov. sp., Skenea minuticostata nov. sp. and Skenea wareni nov. sp. We highlight the first description of a member of the subfamily Thysanodontinae in the Europe faunas. Six are homonyms and receive replacement names: Trochus heliciformis Millet, 1865 is a junior homonym of T. heliciformis von Zieten, 1832, and is renamed Calliostoma biangulatum nov. nom. Trochus millegranus Millet, 1864, is a is a junior homonym of T. millegranus Philippi, 1836, and is renamed Callisotoma milletigranum nov. nom. Trochus torulosus Millet, 1865 is a junior homonym of T. torulosus Philippi, 1845, and is renamed Calliostoma miotorulosum nov. nom. Trochus tumidus Millet, 1865 is a junior homonym of T. tumidus Montagu, 1803, and is renamed Calliostoma miotumidum nov. nom. Trochus echinatus Millet, 1865 is placed in the genus Calliostoma, rendering C. echinatum Dall, 1881 a secondary homonym, which is renamed C. caribbechinatum nom. nov. The following are new subjective synonyms: Emarginula dujardini Dollfus & Dautzenberg, 1886 is considered a junior subjective synonym of Emarginula imbricata Millet, 1865. Gibbula (Colliculus) sosensis Cossmann & Peyrot, 1917 is considered a junior subjective synonym of Trochus insignis Millet, 1854, Monodonta (Oxystele) amedei turoniensis Glibert, 1949 is considered a junior subjective synonym of Pitonellus trochiformis Millet, 1865. This is the most speciose European Neogene Vetigastropod assemblage known, with 31 different genera/subgenera represented. The fauna is highly endemic, with 63% of the species known only from the northwestern French Assemblage I localities. The generic composition is similar to that seen at these latitudes today; a few genera are extinct, such as Lucapinella, Paroxystele and Pareuchelus. Few thermophilic elements are present. The composition of the assemblage represents a hard-bottomed littoral fauna.