It is well known that geographic variation oceurs in life history characteristics among populations of lizards. Variations in life histories found in some studies are possibly adaptations to environmental pressures. In southwestern México, the reproductive characteristics of the endemic species Sceloporus formosus have been poorly studied throughout its geographic range. We used specimens from scientific collections to describe male and female reproductive eyeles and sexual dimorphism of S. formosus. Other viviparous Sceloporus from high elevations show sexual dimorphism, with males being larger in many morphological characteristics than females. We therefore expected that S. formosus would show sexual dimorphism. However, we found no sexual dimorphism.... |