IODP 339 Site U1385 ("Shackleton site", e.g. Hodell et al., 2013a), from the SW Iberianmargin, offers the opportunity to study marine microfossil population dynamics bycomparing several past interglacials and to test natural shifts of species that occurred acrossthese warm periods, in a subtropical context. Here, more specifically, we present resultsobtained for the dinoflagellate cyst (dinocyst) population integrated at a regional scalethanks to the addition of data from proximal sites from southern Iberian margin. Whenpossible, observations made using the dinocyst bio-indicator are compared to additionalproxies from the same records in order to test the synchronicity of the marine biotaresponse. Pollen data available for some of the compiled marine sequences also offer theopportunity to directly compare marine biota with terrestrial ecosystem responses. Thisspatio-temporal compilation reveals that, over the last 800 ka, surface waters around Iberiawere tightly coupled to (rapid) climate changes and were characterised by coherent dinocystassemblage patterns, highlighting a permanent connection between Atlantic andMediterranean waters as evidenced through a continuous exchange of dinocyst populations.Some index species well illustrate the evolution of the regional hydrographic context alongtime, as for instance Spiniferites and Impagidinium species, together with Lingulodiniummachaerophorum, Bitectatodinium tepikiense and heterotrophic brown cysts. Theyconstitute key bio-indicators in context of natural environmental shifts at long and shorttimescales.