Geographic distribution modeling and taxonomy of Stephadiscus lyratus (Cothouny in Gould, 1846) (Charopidae) reveal potential distributional areas of the species along the Patagonian Forests.

A be-lobed kidney, a close secondary ureter, the terminal portion of the uterus forming a compact glandular mass, and the vas deferens with a dilatation are new anatomical information that distinguishes this species. Stephadiscus lyratus inhabit cold native forest areas, mainly living on or under humid logs in contact with the ground. The main constraining variables to explain S. lyratus distribution in the EGD were BIO3, BIO12, BIO6, and BIO4. The potential area of distribution obtained almost duplicates their original range (140,454 km2) extending to the Valdivian Temperate forests mainly in Chile. Natural and semi-natural terrestrial vegetation was predominant in the potential area of distribution of S. lyratus. However, only 14.7% of this area occurs within current protected areas from Argentina and Chile. The ectothermic physiological traits of this species, low dispersal capacity, and its narrow habitat requirements turn S. lyratus into a potentially vulnerable species.