A new species of Megacricetodon from the Early-Middle Miocene of Czech Republic and its importance for the understanding of the earliest evolution and dispersal of the genus in Europe

The sudden appearance of modern cricetids in Europe during the Early Miocene was one of the most significant mammalian events of European Neogene. A characteristic representative of this mammalian turnover was the genus Megacricetodon that quickly became major components of the rodent faunas across Europe. Here, we review the fossil record of this genus from the Early-Middle Miocene (MN4-MN5) localities of Czech Republic, the key area for the understanding the earliest history of this genus in central Europe. We provide an age refinement of the localities under study, especially in the context of new data from the Northern Alpine Foreland Basins. A detailed analysis of the available material revealed a presence of Megacricetodon grueneri sp. nov., described here from Dolnice 3 (MN4a/b). The oldest record of Megacricetodon comes from Ořechov (~late MN4a) and marks the first occurrence of the genus in central Europe. We discuss and propose the most likely scenarios for the earliest phylogeny and dispersal of Megacricetodon into central and western Europe that were strongly influenced by major tectonic processes in the Pannonian and Pre-Alpine areas having a major impact on the development of terrestrial ecosystems and the composition of faunas. Zoobank: http://zoobank.org/urn:lsid:zoobank.org:pub:D2154E84-BD58-4AF9-80C7-8E8AEED7517D