The palaeobiogeography of Subpterynotus Olsson & Harbison, 1953 (Gastropoda: Muricidae) revisited with the description of two Cenozoic new species from Eastern Atlantic

The genus Subpterynotus Olsson and Harbison, 1953 was until very recently a composite genus in which several species, now attributed to Eofavartia Merle, 2002 and Exquisitor Merle, Garrigues and Pointier, 2022, were included. Its revision clarified its distribution in the geological record and the description of two new species, S. eocaenicus nov. sp. from the Bartonian of the Paris Basin and S. mainotensis nov. sp. from the Aquitanian of the Aquitaine Basin, increases our knowledge on the palaeobiogeography of the genus. Subpterynotus eocaenicus nov. sp. extends the First Appearance Datum (FAD) of the genus in the middle Eocene (early Bartonian) of Europe, whereas before it was known only in the upper Eocene (Priabonian). Subpterynotus mainotensis demonstrates the persistence of the genus in the Miocene (Aquitanian) of Europe. As no Subpterynotus is known on tropical western Atlantic coast of America prior to the Burdigalian (Chipola Formation, Florida, USA), its presence suggests an east-west dispersal. The palaeobiogeographic scenario of Subpterynotus is compared to those of Eofavartia Merle, 2002 and Exquisitor Merle, Garrigues and Pointier, 2022, which are also thermophilic taxa. It differs from that of Eofavartia which has a west-east dispersion towards Indo-Pacific and that of Exquisitor whose area is restricted to the Miocene European-West African (tropical) Province for the extinct species and to the south of the Mediterranean-Moroccan Province for the extant Atlantic species.