At the southern fringe: extant and fossil water voles of the genus Arvicola (Rodentia, Cricetidae, Arvicolinae) from Israel, with the description of a new species

Abstract

ABSTRACT The (palaeo)biogeography of water voles is a puzzle that is not solved in detail yet. Extant species of the genus Arvicola cover a vast geographic area of the Palearctic. In this study, we collected morphometric data of extant and fossil Arvicola from Israel at the southern fringe of the water vole distribution area. The dental evolution of water voles is characterised by certain clear trends in the first lower molar (m1) related to crown height, tooth length, the proportion of the anteroconid-complex, and enamel differentiation. Trans-regional correlation of the latter trend shows that it did not develop completely synchronously in all the geographic areas of water voles’ distribution, i.e., not at the same evolutionary rate. Based on the size and geographic distribution, we tentatively consider the Israeli material to belong to an A. persicus group, which facilitates the possibility of future taxonomic subdivision. Among the Israeli material, Late Pleistocene remains from Nahal Mahanayeem Outlet (NMO) show a very particular morphology of the first lower molar compared to samples from other localities in Israel and western Asia, which – in our opinion – justifies the establishment of a new species Arvicola nahalensis n. sp.