I. IGUANIA Cope, 1864

         Frontals fused and generally constricted between orbits; broad shelf from frontal under nasals; postfrontal reduced; dracomorph brain-stem anatomy; m. intercostalis ventralis absent; tongue with mainly serous and sero-mucous mucocytes. Pan-global excepting New Zealand, most of Oceania.

1. CHAMAELEONIDAE Rafinesque, 1815. (6 genera, 128 species of chameleons; 44 genera, 319 species of agamids; generic status of many groups under revision.) This grouping follows Frost & Etheridge (1989), who dispute the monophyly of Agamidae, and at best consider Agamidae* a metataxon. Dentition acrodont, with teeth growing out of crest of tooth-bearing bones; caudal autotomy lacking. Head generally high, round or box-shaped. Old World tropics and sub-tropics.

Key to the Subfamilies of the Chamaeleonidae

1a. Body strongly laterally compressed; head casque-like; eyes turret-like, largely covered by skin and  with a tiny, round aperture; head sub-triangular; feet without palms/soles (zygodactylus); digits fused into groups of 2 and 3

Chamaeleoninae

1b. Body depressed or, if compressed laterally, with distinct dorsal keel; eyes normal, with functional lids; head rounded, snout obtuse; palms/soles present, digits free and distinct.                      

2

 2a. Premaxilla with enlarged downward, tooth-like growth; canines small in young, fused to premaxillary tooth in adults; body strongly depressed

Leiolepidinae

2b. Premaxillary teeth normal; an anterior pair of canine-like teeth in both jaws

Agaminae

         1. Agaminae.   
                                       Pogona henrylawsoni, known as Rankin's dragon..

                  Epiotic foramen present (except in Moloch); lacrimal foramen enlarged; interclavicle present; paired, enlarged sternal fontanelles; postxiphisternal inscriptional ribs short; head shortened, sub-spherical; hind-limbs thin; enlarged canine-like teeth on both jaws. Africa, southern Asia, and Australia.

                  2. Leiolepidinae.  

Uromastyx benti.

                  Epiotic foramen absent; lacrimal foramen not enlarged; interclavicle present; paired sternal fontanelles; postxiphisternal inscriptional ribs short; head shortened, nearly spheroid; teeth normal, acrodont. Deserts of North Africa, southwest Asia, and tropics of southeast Asia.

Key to the Genera of Leiolepidinae

1a. Tail slightly longer than SVL, strongly spinose                         Uromastyx

1b. Tail long, normally scaled                                                       Leiolepis

                  3. Chamaeleoninae.

                  Lacrimal foramen extremely enlarged; epiotic foramen and interclavicle absent; sternal fontanelles absent; postxiphisternal inscriptional ribs long, fused medially; zygodactyl feet; body laterally compressed; head casqued, laterally compressed; tongue extremely elongate, protrusible; eyelids fused, with tiny aperture for vision; ears concealed. Southwest Europe, southwest Asia, Africa, Madagascar, Seychelles, India, and Sri Lanka.

B. SUPERFAMILY IGUANOIDEA (=FAMILY IGUANIDAE)

         Similar to Agaminae from which they differ in having pleurodont dentition (as do all lizards excepting Chamaeleonidae), with the teeth uniform in structure within an individual; snout slightly depressed and elongated such that head is rarely perceived as spherical; eyelids present; autotomy common; limbs present, pentadactyl (= 5-fingered). New World generally, from Canada south to Argentina, and extralimital in Fiji and Madagascar. Generally considered a single family in literature prior to 1990, but convention has accepted the division of the taxon into numerous smaller families as given here.

         A. CORYTHOPHANIDAE. (3 genera.) Males with conspicuous nuchal, and often dorsal, casque and/or crest. Limbs long. Central and northern South America. Basilisks, cone-heads and crested lizards.

         B. CROTAPHYTIDAE. (2 genera) Head large, distinct from neck; dorsal scales granular; femoral pores present; autotomy absent. Southwestern United States and northern Mexico.

         C. HOPLOCERCIDAE.

         D. IGUANIDAE. (6 genera.) Low, serrated dorsal crest present; head rounded, blunt; teeth tricuspid. Generally herbivorous. Southern United States south to Argentina, extralimital in Fiji and Galapagos Islands. Iguanas.

         E. OPLURIDAE.

         F. PHRYNOSOMATIDAE.

         G. POLYCHRIDAE (anoles).

         H. TROPIDURIDAE.