The Vertebrate Fossil Assemblage From Stăuceni (Botoșani County, Northeastern Romania): A Mixture of Miocene and Pliocene–pleistocene Elements Revealing a Complex Sedimentary Evolution Along the Margin of the East European Platform

The fluvial deposits exposed at Stăuceni (northeastern Romania) have traditionally been assigned to the Miocene, due to the presence of cetaceans and seals. However, further investigation of the site has yielded additional fossils indicating a more complex depositional history of the site. Several fossiliferous layers, from the bottom to the top of the succession, yielded a mixed vertebrate assemblage including Miocene (kentriodontid and cetotheriid cetaceans, hipparion equids, sparid and merlucciid fishes) and Pliocene–Pleistocene (bovid artiodactyls, soricid eulipotyphlans, arvicoline, murid, sciurid, and spalacid rodents, lagomorphs, esocid and cyprinid fishes) taxa. The occurrence of Microtus (Microtus) nivaloides and Arvicola cf. A. mosbachensis supports a Middle Pleistocene age for the sedimentary succession, which contains reworked Miocene vertebrates, and rare Miocene foraminifers. The occurrence of Upper Pliocene palynomorphs suggests that Upper Pliocene units are also present at the very base of the succession. The mixed vertebrate assemblage from Stăuceni is not only significant for a better understanding of the local depositional setting, but also represents the only known site in Romania east of the Carpathians where Middle Pleistocene small mammals have been identified, thus providing important palaeogeographic information for this group. The occurrence of merlucciid remains is also unique for the East European Paratethyan realm, adding to the palaeobiogeographic importance of the site.