Biogeographical scenario for Triturus in response to the last glacial to current interglacial climate shift. Shown are the inferred approximate positions of glacial refugia (dark shades) and postglacially colonized area (light shades; arrows reflect approximate colonization routes). Areas where species displaced one another (containing asymmetrically introgressed mitochondrial DNA) are shown in grey. For T. dobrogicus, neither the genetic nor species distribution modeling approach manages to recover a refugium (reflected by question marks). See text for further details.
Wielstra et al. Frontiers in Zoology 2013 10:13 doi:10.1186/1742-9994-10-13