The genus Triturus comprises the marbled newts (such as T. pygmaeus on the left) and the crested newts (such as T. karelinii on the right). Pictures by Michael Fahrbach.

Despite the genus Triturus (in my humble opinion) being a model system in evolutionary research , the phylogenetic relationships among the different crested newt species have never been resolved. In a paper published in Contributions to Zoology, we consulted allozyme and mitochondrial DNA data to try and rectify this situation. However, despite the large amount of data, we did not manage to improve on the situation. The fuzziness of crested newt relationships might well reflect an actual simultaneous split. We compare time estimates of the crested newt radiation for the allozyme and mitochondrial DNA dataset. We conclude that only the latter can be brought in line with potential geological drivers and provide a biogeographical scenario. This paper was a good opportunity to split the distinct T. macedonicus from T. carnifex, we thought.

Reference: Arntzen, J.W., Esprequeira Themudo, G., Wielstra, B. (2007). The phylogeny of crested newts (Triturus cristatus superspecies): nuclear and mitochondrial genetic characters suggest a hard polytomy, in line with the paleogeography of the centre of origin. Contributions to Zoology 76(4): 261-278.