55 Joannea Geol. Paläont. 9: 55-57 (2007) Terminal Miocene Events in the Pannonian Basin Imre MAGYAR & Orsolya SZTANÓ The Late Miocene Messinian age has witnessed profound palaeogeographic re-arrange- ments both in the Mediterranean and in the Paratethyan realms (POPOV et al. 2006). These included the Messinian salinity crisis, commonly interpreted as a complete de- siccation of the Mediterranean Basin (HSÜ et al. 1977), and at least a significant base- level drop, if not total desiccation, of the Black Sea and Dacian Basins (HSÜ & GIOVANOLI 1979; CLAUZON et al. 2005; GILLET et al. 2006). Another common feature shared by the two realms is the sudden appearance of a characteristic brackish water fauna in the post-salinity crisis “lagomare” of the Mediterranean (ESU 2007) and at the beginning of the Pontian age in the Eastern Paratethys (NEVESSKAJA et al. 1987). How did these events affect the Central Paratethyan Pannonian Basin? Many auth- ors argued that the Pannonian Basin became part of a united Paratethys at the begin- ning of the Pontian, and that Eastern Paratethyan Pontian fauna, first of all cardiid bi- valves, entered and conquered the basin at that time (NEVESSKAJA et al. 2001). Study of seismic reflection profiles led some authors to argue that the Pannonian Basin expe- rienced a large-scale (several hundred metre) base-level drop at about the time of the Messinian salinity crisis (CSATÓ 1993). According to this view, the Pannonian Basin shared the history of the Eastern Paratethys: it received a new mollusc fauna immigra- ting from an adjacent basin at the beginning of the Pontian, and experienced significant lowering of water level during the late Messinian salinity crisis. Several lines of evidence, however, indicate that this might not be the correct in- terpretation of the palaeontological and seismic record. In fact, all early Pontian cardiid genera of the Black Sea Basin, with the single exception of Eupatorina, have a long stratigraphic record well back into the Tortonian within the Pannonian Basin. The first representatives of Euxinicardium, Pseudocatillus, and Paradacna appear before 9.5 Ma in the deposits of Lake Pannon. Prosodacnomya originated from the “Lymnocardi- um” decorum group around 8 million years ago (MÜLLER & MAGYAR 1992). The first known representative of Pontalmyra, P. budmani, is also at least as old as 8 Ma. “Eu- xinicardium” subodessae of the Black Sea Basin corresponds to “Euxinicardium” oche- tophorum of the Pannonian Basin, the latter originating from “Lymnocardium” vicinum sometime between 8 and 7 Ma. During most of the Tortonian age, Lake Pannon was the only waterbody inhabited by endemic brackish lacustrine cardiids (subfamily Lym- nocardiinae).