Aliveri revisited, a biogeographical appraisal of the early Miocene mammals from the eastern Mediterranean

At the time of its discovery, over 25 years ago, the Greek locality of Aliveri preserved the easternmost occurrence for the early Miocene of cricetodontine hamsters such as Cricetodon, Megacricetodon and Democricetodon. As knowledge on the early Miocene history of the eastern Mediterranean increased, the faunal composition became more enigmatic, because of the presence of typical European elements (Pseudotheridomys, Heterosorex, Plesiodimylus, Myxomygale), absent from Anatolia. Recently, the ungulates from the locality were rediscovered, expanding the faunal list with the equid Anchitherium and the pecorans Lagomeryx (two species), Eotragus and Palaeomerycidae gen. et sp. indet. In this paper, we examine the fauna of Aliveri in the light of the current state of knowledge. The assemblage is typical for MN 4, but is believed to pre-date European localities of that biochronological unit. Similarity with Anatolian MN 3 localities suggests that the origin of the fauna lies mostly in that region, whereas the major differences with European localities suggest relative isolation, in line with palaeogeographic reconstructions of the period. However, when isolation was lifted, a number of European elements were added to the local fauna, but, presumably because of an ecological barrier, did not move further into Anatolia. Migrations at the onset of MN 4 can explain the composition of the Greek fauna, but we are still far from completely understanding the complex history of the eastern Mediterranean during the early Miocene.