A new alpine newt species from the Vlasina region of Serbia and Bulgaria

The ‘alpine newt’ has long been suspected to comprise multiple cryptic species. A recent phylogenomic study recognized five different species of alpine newt. For four of these species a name was already available under the Principle of Priority. We here provide a species description for the fifth species: Mesotriton similis sp. nov. The new species inhabits the Vlasina Plateau and surroundings, in southeastern Serbia and adjacent western Bulgaria. It is sister to a clade containing M. alpestris, M. apuanus, and M. reiseri, and differs from all its congeners, including the parapatrically occurring M. reiseri, by a substantial genomic divergence.