Crotaphytidae

The Crotaphytidae, or collared lizards, are a family^[1][2][3] 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.

Crotaphytidae
Crotaphytus collaris
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Iguania
Infraorder:	Pleurodonta
Family:	Crotaphytidae H.M. Smith & Brodie, 1982
Genera
Crotaphytus Gambelia

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.^[4][5]

Technical characters

• Femoral pores present
• Interparietal scale small (distinctly smaller than ear opening)
• Never have an enlarged middorsal scale row or fringe
• Never have a divided rostral scale
• No bony spines or projecting ridges on their heads
• No scales projecting over their ears, and no scales forming a prominent fringe on sides of toes as in Phrynosomatidae

Species

Image	Genus	Living species
	Gambelia Baird, 1859[6][7] (leopard lizards)	Gambelia copeii – Cope's leopard lizard (Yarrow, 1882) Gambelia sila – Blunt-nosed leopard lizard (Stejneger, 1890) Gambelia wislizenii – Long-nosed leopard lizard (Baird & Girard, 1852)
	Crotaphytus Holbrook, 1842[6][8] (collared lizards)	Crotaphytus antiquus – Venerable collared lizard Axtell & Webb, 1995 Crotaphytus bicinctores – Desert collared lizard N.M. Smith & W.W. Tanner, 1972 Crotaphytus collaris – Common collared lizard (Say, 1823) Crotaphytus collaris auriceps – yellow-headed collared lizard Fitch & W. Tanner, 1951 Crotaphytus collaris baileyi – western collared lizard Stejneger, 1890 Crotaphytus collaris collaris – eastern collared lizard (Say, 1823) Crotaphytus collaris fuscus – Chihuahuan collared lizard W. Ingram & W. Tanner, 1971 Crotaphytus collaris melanomaculatus – black-spotted collared lizard Axtell & Webb, 1995 Crotaphylus dickersonae – Dickerson's collared lizard K.P. Schmidt, 1922 Crotaphytus grismeri – Grismer's collared lizard McGuire, 1994 Crotaphylus insularis – Eastern collared lizard Van Denburgh & Slevin, 1921 Crotaphytus nebrius – Sonoran collared lizard Axtell & Montanucci, 1977 Crotaphytus reticulatus – Reticulated collared lizard Baird, 1858 Crotaphytus vestigium – Baja collared lizard N.M. Smith & W.W. Tanner, 1972

Nota bene: A binomial authority in parentheses indicates that the species was originally described in different genus.