A new perspective on the molecular dating of the stone crayfish with an extended phylogeographic information on the species

Reconstructing the origin and historical biogeography of the Austropotamobius torrentium is hampered by insufficient phylogeographic coverage of the Balkans and deep contradictions in previous molecular dating. The present work extends the phylogeographic coverage to Serbia, a country crucial for understanding the species southward dispersal. Our analysis revealed that the Southern Balkans lineage occurs in most of the country, the Central and southeastern Europe lineage is restricted to the southwest and northeast of the country, while a single population in the north of the country harbors the Lika and Dalmatia lineage, which was previously thought to be restricted to the northern-central Dinarides. Dataset expansion led to revised phylogenetic relationships, which indicated that the Apuseni lineage is not nested within Northern-central Dinarides lineages but arose after the most basal split within Austropotamobius torrentium. This ‘Apuseni first’ phylogeny provides a new perspective for molecular dating, according to which the split between Austropotamobius pallipes and A. torrentium took place in the Late Oligocene, while the formation of the phyletic lineages and the dispersal from the Dinarides to Serbia occurred in the late Miocene and is probably associated with the complex and protracted process of disintegration of the Neogene freshwater lakes in southeastern Europe.