140 University of California Publications in Zoology 



62-A. Dorsal midsagittal fins of caudal vertebrae anterior to neural spines relatively 

 large and present well beyond anterior third of caudal sequence. 



63- A or -B. Postxiphisternal inscriptional ribs do not form continuous chevrons, or 

 anteriormost pairs do only variably. 



64-A. Suprascapulae oriented primarily vertically and form a continuous arc with the 

 scapulocoracoids. 



65- A. Scapular fenestrae present and large. 



66-A. Posterior coracoid fenestrae absent. 



67- A. Clavicles wide, with prominent lateral shelves. 



68-A. Posterior process of interclavicle extends well beyond lateral corners of 

 sternum. 



69-A. Interclavicle arrow-shaped, lateral processes forming angles of less than 75° 

 with posterior process. 



70- A. Sternal fontanelle present and of moderate size. 



71-A. Sternum diamond-shaped, xiphisternal rods attach close to midline. 



72-A. Pelvic girdle relatively long and narrow. 



73-A. Large anterior iliac process. 



74-A. Cephalic osteoderms absent. 



75-A. Heart lies entirely anterior to transverse axillary plane. 



76- A. Subclavian arteries covered ventrally by posterior end of M. rectus capitis 

 anterior. 



77- A. Right and left systemic arches unite to form dorsal aorta above heart. 



78-A. Coeliac artery arises from dorsal aorta anterior to and separate from mesenteric 

 arteries. 



79-A. Colic wall with one or more transverse valves. 



80-A. All colic valves semilunar. The polarity of this character is questionable. 



81- A. Median azygous rostral scale present. 



82-A. Snout scales small and numerous, approximately same size as those of 

 supraorbital and temporal regions. 



83-A. Dorsal head scales flat or only slighdy convex. 



84-B. Superciliary scales moderately elongate and partially overlapping. It is also 

 possible that the ancestral iguanine had elongate and strongly overlapping superciliaries. 



85-A or -B. Subocular scales subequal in size, or one or two moderately elongate. 



86-A. Anterior auricular scales small or only slighdy enlarged. 



87- A. Gular fold well developed. 



88- A. Dewlap small or absent. The polarity of this character is questionable. 



89-A. Gular crest of enlarged scales absent. 



90-A. Middorsal scale row present. 



91-A. Pedal subdigital scales asymmetrical, anterior keels larger than posterior ones. 



92- A. Pedal subdigital scales lack greatiy enlarged anterior keels fused at their bases to 

 form combs. 



93-A. Toes unwebbed. 



