Phylogenetic Systematics oflguanine Lizards 



FIG. 2. "Grouping and possible phylogeny of the genera of iguanids occurring in the United States," 

 after H. M. Smith (1946:92). Roman numerals apparently refer to the following: (I) leaf-toed section, (II) 

 herbivore section, (III) sand-lizard section, (IV) rock-lizard section, (V) pored utiform section, (V) horned- 

 lizard section, and (VII) poreless utiform section. 



distinguished by marked differences in vertebral and nasal structures and include 

 several genera not usually recognized as being allied to Nearctic forms. (Savage, 

 1958:48) 



Savage's "iguanine line" contained Amblyrhynchus, Brachylophus, Conolophus, 

 Crotaphytus, Ctenosaura, Cyclura, Dipsosaurus, Enyaliosaurus {=Ctenosaiira, part), 

 Iguana, and Sauromalus. This group was distinguished from the "sceloporine line" by two 

 primary characters: the presence of accessory vertebral articulations, the zygosphenes and 

 zygantra, and the possession of a relatively simple, S-shaped nasal passage with a concha 

 present (Dipsosaurus-lypt of Stebbins, 1948). Other osteological and integumentary 

 features characteristic of the majority of the genera in each line were also given. 



