University of California Publications in Zoology 



Streptosaurus 

 Petrosaurus -^ 

 Crotaphytus 



Callisaurus 



Uma 

 Holbrookia 



Uta ,, 



y Urosaurus 



\ /" 



Sceloporus 



\ 



Sator 



Phrynosoma 



Dipsosaurus 



Ctenosaura 



Primitive Iguanid Type 



FIG. 1. "The phylogeny and relationships of North American iguanid genera," after Mittleman 

 (1942:113). 



States. In addition to the three genera found in or near the United States, Smith's herbivore 

 section contained other "large, primitive iguanids," namely Amblyrhynchus, Conolophus, 

 Cyclura, and Iguana. Smith's Handbook dealt with the lizards of the United States and 

 Canada; those iguanines whose ranges did not enter this area were apparently omitted from 

 his phylogram for convenience. In any case. Smith could not have considered his 

 herbivore section to be monophyletic in the more restricted modem sense, since the group 

 was considered to be ancestral to other North American iguanids. 



Savage (1958) explicitly challenged Mittleman's (1942) implication that the North 

 American iguanids formed a natural group: 



Insofar as can be determined at this time, the so-called Nearctic iguanids form two 

 diverse groups that can only be distantly related. These two sections are 



