The genus Solariella (Mollusca, Archaeogastropoda) from the Pliocene of Vale de Freixo, Portugal: palaeobiogeographic and palaeoclimatic implications

In the present paper, the trochid gastropod Solariella cincta (Philippi, 1836) is recorded for the first time from Pliocene (Piacenzian) strata exposed at Vale de Freixo (Pombal, central-west Portugal). This record of the species constitutes the first from the Atlantic Neogene; the taxon is here compared with other Miocene to Recent European species of Solariella. At present, S. cincta is restricted to the coast of West Africa. During the Late Pliocene, it had a much wider distribution, occurring in the Mediterranean and along the European Atlantic coasts, at least as far north as central-west Iberia. The presence of thermophilic benthic gastropods such as S. cincta, Tribia uniangulata (Deshayes, 1830), Solatia piscatoria (Gmelin in Linné, 1790), Ancilla sp., Ficus sp., and Strioterebrum sp. in Pliocene strata at Vale de Freixo, clearly indicates that relatively high water temperatures (i.e. warmer than today) still prevailed, at least sporadically, along the European Atlantic coast at this latitude, between c. 3.2-3.1 and 2.7 Ma.