Single dates obtained on mollusk shells by the U-series nuclides method are highly unreliable, primarily because of the mobility of uranium isotopes. However, in several cases, a statistical approach was demonstrated to yield coherent chronologies in both continental and marine environments. We report on 34 new Th and U isotope measurements on Strombus bubonius and Glycymeris glycymeris fossils from raised marine terraces in the Almeria area, southeastern Spain. The results yield a coherent chronology that indicates the presence of the warm water S. bubonius fauna in the Mediterranean basin at the end of the Mindel-Riss interglacial (18O stage 7) and during each high sea-level episode of the Riss-Würm interglacial (18O stage 5). Reconsideration of the Tyrrhenian stratigraphy based on the presence of S. bubonius is thus required.