The Phrynosomatidae are a diverse family of lizards, sometimes classified as a subfamily (Phrynosomatinae), 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. The earliest fossil remains of this group are known from the Late Cretaceous of Mongolia and belong to the genus Desertiguana. As phrynosomatids are only known from North America, these remains indicate that phrynosomatids likely had a wider distribution in prehistoric times.

Genera

The Phrynosomatidae are organised into nine genera. The earless taxa (Cophosaurus and Holbrookia) are sister genera. Family Phrynosomatidae