Biogeography and evolution of the Smooth snake Coronella austriaca (Serpentes: Colubridae) in the Iberian Peninsula: evidence for Messinian refuges and Pleistocenic range expansions

TLDR: The results indicate that Coronella austriaca presents at least three mtDNA lineages in Iberia that may have originated during the Messinian Salinity Crisis, 5.3-5.9 Ma, and support the more recent view that the accentuated environmental instability occurred during the Pleistocene did not lead to speciation in many animal groups.

Abstract: The European Smooth snake, Coronella austriaca Laurenti, 1768, presents a continuous distribution range across central and northern Europe, with isolated fragmented populations in the southern European peninsulas. Up to 814 bp of mitochondrial DNA from 34 specimens were used to determine the phylogeny and biogeography of this species within the Iberian Peninsula. The results indicate that Coronella austriaca presents at least three mtDNA lineages in Iberia that may have originated during the Messinian Salinity Crisis, 5.3-5.9 Ma. Posterior range shifts within the independent clades were facilitated by climatic fluctuations that occurred during the Pleistocene Ice Ages and, in the Iberian Peninsula, created a complex scenario of refugia-within-refugia. The formation of old allopatric lineages during the Messinian followed by shifts in the distribution range during the Pleistocene coincide with what has been reported for other Iberian reptiles and amphibians and highlights the importance of the Southern European Peninsulas as "old" hotspots of biodiversity. Our results also support the more recent view that the accentuated environmental instability occurred during the Pleistocene did not lead to speciation in many animal groups. The subspecific status of C. a. acutirostris is confirmed by the mtDNA analyses.