Quaternary range dynamics and taxonomy of the Mediterranean collared dwarf racer, Platyceps collaris (Squamata: Colubridae)

Abstract The geological and geographical settings of the Eastern Mediterranean have resulted in complex patterns of intraspecific diversifications and phylogeographical histories that can be observed in squamates. In this study, we examined genetic differentiation of the Collared dwarf racer (Platyceps collaris) using a multilocus genetic dataset with a sampling that covered the entire range of the species. We developed distribution models in current and past climatic conditions to assess the dynamics of the species distribution through time. We sequenced a fragment of the cytochrome b mitochondrial gene of the holotype and eight paratypes of Coluber rubriceps thracius, which is considered a synonym of Platyceps collaris. Our results show that there are two distinct clades within P. collaris, one occupying the Balkans and western and southern Anatolia (termed the Balkan–Anatolian clade), the other in the Levant (termed the Levantine clade). All type specimens of C. r. thracius are genetically identical and cluster within the Balkan–Anatolian clade. Distribution models indicate the presence of two refugia during climatically challenging periods. One was in western Anatolia and served as a source for the colonization of the Balkans and southern Anatolia, and the other was in the northern Levant, from where P. collaris dispersed further south. According to our results, we revise the subspecific taxonomy of P. collaris.