Genus Apodemus in the Pleistocene of Central Europe: when did the extant taxa appear?

Abstract

Abstract The extant species of the genus Apodemus represent the most common small mammals of Central Europe. Unfortunately, their phylogenetic past is only poorly known. With the aid of detailed biometric analyses we tried to identify the first appearance of the phenotypic patterns characterizing the extant populations. We examined dental material of Apodemus from 53 community samples from the territory of the Czech Republic and Slovakia dated from the early Villanyian (MN 16/17) to the late Middle Pleistocene (Q 3) with particular respect to their correspondence with the morphometric characteristics of the extant species. While the Toringian (Q 3) interglacial samples invariably include forms identical with the extant taxa A. flavicollis, A. sylvaticus and supposedly A. uralensis (including the items corresponding to A. maastrichtiensis), the samples of Early Pleistocene age (MN 17 – Q 2) exhibited clear differences in the variation pattern which results in questioning the possibility of their co-identification with the respective extant species. In most instances they varied within the limits in resembling A. sylvaticus but exceeded its variation ranges in some non-metric characters. Regarding serious doubts on real taxonomic status of other named fossil species we propose to denote these Plio-Pleistocene sylvaticus-like phenotypes provisionally with the prior name A. atavus Heller, 1936.