For almost 200 years the rich and diverse Pliocene central Mediterranean molluscan assemblages have been described in detail. However, only relatively recently has the importance of the Iberian Pliocene deposits been recognised. The few systematic works published to date on the Huelva Sands Formation gastropod assemblage do not do justice to its less common species. They do not describe the cohort of endemic specific taxa, nor do they focus on the groups which reflect a West African influence, absent in the Central Mediterranean Pliocene.
In The Lower Pliocene gastropods of the Huelva Sands Formation, Guadalquivir Basin, Southwestern Spain we review the Lower Pliocene gastropod assemblage of the Huelva Sands, Guadalquivir Basin (SW Spain). 269 species are recorded and illustrated, and in some cases taxonomic notes where added. The geological and stratigraphical setting is summarised and their palaeobiogeographic significance discussed. Despite some notable differences between the Huelva southern Iberian Lower Pliocene Atlantic assemblage and the coeval assemblages found within the Mediterranean, during the Early Pliocene the Atlantic Southern Iberian faunas were part of the Mediterranean-West African Biogeographical Province, representing the northern limit of this tropical bioprovince.