Figure 1

A) Geographic distributions of all species of European Hydromantes ; B) Measurements used to characterize foot morphology; C) photo of Hydromantes (S.) strinatii (courtesy of S. Vanni). Foot morphology in European Hydromantes was quantified in several ways, following [27]: 1) foot shape, as defined by the positions of nine anatomical landmarks (numbered), 2) the degree of foot webbing, found as the ratio between the perimeter of the foot (p) divided by foot width (d), 3) foot area (A) enclosed by the outline of the entire foot. The species examined in this study are: H. (S.) ambrosii, H. (S.) flavus, H. (S.) genei, H. (S.) imperialis, H. (S.) italicus, H. (S.) sarrabusensis, H. (S.) strinatii, and H. (S.) supramontis.