Snakes of the pseudoboine genera Clelia, which is probably polyphyletic, and Boiruna are distributed from southern Argentina, southern Brazil, and Uruguay northwards into central México. Six members occur in Paraguay and Argentina: B. maculata, Clelia bicolor, C. clelia, C. plumbea, C. quimi, and C. rustica. Historically, there has been taxonomic confusion among the larger species (B. maculata, C. clelia, C. plumbea, and C. rustica) and between the small species (C. bicolor and C. quimi). All of the species except C. rustica have distinct ontogenetic color changes. Species can be distinguished on the bases of size, color, hemipenial spines, and loreal, supralabial, and ventral scale counts. Much of the morphological evolutionary differentiation in Boiruna... |