Geometric morphometrics plays an important role in evolutionary studies. The state of the art in this field are landmark-based methods. Since landmarks usually need to be placed manually, only a limited number of landmarks are generally used to represent the shape of an anatomical structure. In this project, we try to overcome this limitation by applying a surface-based shape-model approach to analyze the variation of the para-basisphenoid complex of snakes of the genus Eirenis. The first goal is to generate a surface-based shape model incorporating all 18 species of this genus. In a subsequent step, we plan to apply this shape model to study the correlation between shape and general living conditions including habitat and feeding habits.