The Crotaphytidae, or collared lizards, are a family of desert-dwelling reptiles native to the Southwestern United States and northern Mexico. Alternatively they are recognized as a subfamily, Crotaphytinae, within the clade Pleurodonta. They are very fast-moving animals, with long limbs and tails; some species are capable of achieving bipedal running at top speed. This species is carnivorous, feeding mainly on insects and smaller lizards. The two genera contain 12 species.

They may be related to the extinct Arretosauridae of Paleogene Asia due to similar jaw morphologies, though other studies classify the Arretosauridae in Acrodonta with other Old World iguanians.

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