The Phrynosomatinae are a diverse subfamily of lizards, previously known and sometimes incorrectly classified as Phrynosomatidae, found from Panama to the extreme south of Canada. Many members of the group are adapted to life in hot, sandy deserts, although the spiny lizards prefer rocky deserts or even relatively moist forest edges, and the short-horned lizard lives in prairie or sagebrush environments. The group includes both egg-laying and viviparous species, with the latter being more common in species living at high elevations.