Phylogenetic Systematics oflguanine Lizards 



mid-1960's the iguanines had been resurrected as a natural group, the same group that 

 Cope (1900) had recognized at the turn of the century. 



In his landmark paper on squamate systematics. Classification of the Lizards, Camp 

 (1923) dealt primarily with the interrelationships of the lizard families. Nevertheless, his 

 treatise contains scattered but intriguing comments on relationships at lower taxonomic 

 levels. About the throat musculature of iguanines, he said: 



In the "Cyclura group" comprising the genera Iguana, Amblyrhynchus, 

 Ctenosaura, Brachylophus, Sauromalus, and Cyclura, the superficial bundle [of the 

 M. mylohyoideus anterior] is very specialized and consists of definitely directed 

 fibers not connected with the skin. Detailed resemblances are present in this group 

 which I have outlined in manuscript and which will not be repeated here. Suffice it 

 to say that the group appears to be a natural one, on the basis of the musculature 

 with close resemblances prevalent between Sauromalus and Cyclura, and 

 Ctenosaura and Brachylophus. (Camp, 1923:371) 



Unfortunately, the whereabouts of the manuscript mentioned in this passage are unknown 

 tome. 



Mittleman (1942) reviewed the genus Urosaurus and commented briefly on the 

 relationships among the genera of North American iguanids, except Anolis. He implied 

 that the North American iguanids formed a monophyletic group descended from 

 Ctenosaura (Fig. 1) and that the similarities among Ctenosaura, Dipsosaurus, and 

 Sauromalus were retained primitive features: 



Dipsosaurus is probably the most primitive of the North American Iguanidae 

 (excepting Ctenosaura, which is properly a Central and South American form), and 

 possesses several points in common with Ctenosaura, most easily observed of 

 which is the dorsal crest; the genera further show their relationship in the similarity 

 of the cephalic scutellation which is essentially simple, and shows no particular 

 degree of differentiation. Sauromalus is considered a specialized offshoot of the 

 Crotaphytus, or more properly, prQ-Crotaphytus stock, by reason of its solid 

 sternum, as well as the five-lobed teeth; the simple type of cephalic scalation 

 indicates its affinity with the more primitive Dipsosaurus-Ctenosaura stock. 

 (Mittleman, 1942:112-113) 



H. M. Smith (1946:92) seemed to adopt a modified version of Mittleman's views on 

 the phylogeny of North American iguanids (Fig. 2). His herbivore section {Ctenosaura, 

 Dipsosaurus, and Sauromalus) was considered to be ancestral to the other North American 

 Iguanidae, save Anolis, with Sauromalus hypothesized to share a more recent common 

 ancestry with these other iguanids than with either Ctenosaura or Dipsosaurus. Smith's 

 subsequent comments (1946:101), however, indicate that he recognized affinities of 

 Ctenosaura, Dipsosaurus, and Sauromalus to iguanids occurring outside of the United 



