The Triturus karelinii-group of crested newts comprises three mitochondrial DNA lineages, but no morphological differences are known. In a paper published in Zoologischer Anzeiger we analyse skull shape to see if there are differences between lineages. While we do not find three discrete geographical groups, the observed differences among lineages are also not smaller than between lineages and another crested newt species, T. macedonicus. We just need to keep looking for morphological differences.

Reference: Ivanović, A., Üzüm, N., Wielstra, B., Olgun, K., Litvinchuk, S.N., Kalezić, M.L., Arntzen, J.W. (2013) Is mitochondrial DNA divergence of Near Eastern crested newts (Triturus karelinii group) reflected by differentiation of skull shape? Zoologischer Anzeiger 252(2): 269-277.