Phylogenetic relationships and divergence dating in the Glass Lizards (Anguinae).

The Glass Lizards are a subfamily (Anguinae) of Anguid Lizards with an elongated limbless body plan that occur throughout the Northern Hemisphere primarily in North America, Europe, and Asia, but also have a presence in North Africa and Indonesia. We used twenty-five nuclear loci (15,191 bp) and 2090 bp of the mtDNA genome to generate a phylogeny containing all known species groups to explore species relationships within the group as well as divergence dating. We also examined the group in the context of a coalescent species tree analysis and species delimitation. All major lineages were found to be monophyletic with potential cryptic diversity in some. The Anguinae first appeared in the Eocene and most lineages were present by the beginning of the Miocene. The Anguinae originated in Europe from an Anguidae ancestor that crossed the Thulean land bridge, spreading to Asia after the drying of the Turgai Sea, then across Beringia as the climate permitted. A species tree analyses found support for the major Anguinae lineages and species delimitation supported accepted species.