Skull comparison between Eirenis collaris and Dolichophis jugularis (Serpentes: Colubridae) from Iran

Two species of the family Colubridae were compared based on cranial osteology. The specimens were from Kermanshah province (2010–2012). We compared the skulls of the two species and distinguished their differences. According to our study, eight elements of the skull are clearly different between the two species. These differences are speculated to relate to different diets, prey size or concluded from an evolutionary processes to adapt especial conditions or competition with other sympatric species. Differences and characteristics of the above species help to facilitate their identification and evaluate phylogenetic studies in relation to skull morphology.