Biogeography of Iberian Atlantic Neogene marginelliform gastropods(Marginellidae, Cystiscidae): global change and transatlantic colonization

The Marginellidae Fleming and the Cystiscidae Stimpson, herein collectively referred to as marginelliform gastropods, are convergent families of thermophilic marine gastropods. Shallow-water marginelliform gastropods are found in the Ibero-Moroccan Gulf and Mediterranean, diversity rapidly increasing towards tropical West Africa. Surprisingly, in the tropical and subtropical European Miocene fossil record, marginelliform genera of tropical affinity such as Persicula Schumacher and Prunum Herrmannsen, occurring today in West Africa, are altogether missing. Others, such as Marginella Lamarck, are present only in the southwestern Iberian and Mediterranean Neogene record. This work describes the marginelliform gastropods from the Atlantic Iberian Neogene. Ten species are recorded, of which three are new, Persicula mikhailovae n. sp., Gibberula costae n. sp., and Gibberula brebioni n. sp. This study shows that Gibberula Swainson and Volvarina Hinds have been present in Europe since the Eocene. Marginella may have originated in southern Africa and migrated north to Europe in the Miocene, never extending further north than west central Portugal. Persicula and Prunum probably originated in the Caribbean and migrated east during the Pliocene, following closure of the Central American Seaway. The colonization of the Pliocene European Atlantic coast by gastropods of these genera was selective, only where high sea-water temperature and high productivity were combined. These findings suggest that post-Messinian recolonization of the Mediterranean during the Pliocene was a complex process, involving colonization by groups originating in various regions of the Atlantic, including Europe, Africa and the Americas.