University of California Publications in Zoology 



were not explicitly included with the rest of the iguanines in an exclusive group. The 

 concept of an iguanine group, exclusive of Dipsosaurus and Sauromalus, was refined with 

 more detailed anatomical descriptions. Beginning with Boulenger's (1885) monumental 

 Catalogue of the Lizards in the British Museum, I undertake here a more detailed 

 chronological treatment of the history of iguanine higher systematics. 



Boulenger (1885) listed all of the genera that are now called iguanines in a nearly 

 continuous sequence in his catalogue, reflecting their position in his key as those iguanids 

 having femoral pores and the fourth toe longer than the third but lacking spines on the head 

 and an enlarged occipital scale. Nevertheless, the distantly related Hoplocercus (Etheridge 

 in Paull et al., 1976) breaks the continuity of the iguanines in the list, and, in terms of 

 Boulenger's characters, some iguanines are closer to certain non-iguanine iguanids than to 

 other iguanines. Boulenger did not explicitly delimit subgroups within Iguanidae or any 

 other family, and we can only guess about his precise ideas concerning such relationships. 



Cope (1886) appears to have been the first to use the name Iguaninae as a formal taxon 

 for iguanine lizards. He further provided characters, both external and skeletal, by which 

 members of this group could be distinguished from other iguanids. Cope's Iguaninae 

 included Cyclura, Ctenosaura, Cachryx, Brachylophus, Iguana, Conolophus, and 

 Amblyrhynchus, but failed to include Dipsosaurus and Sauromalus. The genera 

 Aloponotus and Metopoceros were synonymized with Cyclura. 



In response to Cope, Boulenger (1890) provided what he considered to be osteological 

 evidence for the separation of Metopoceros and Cyclura, and briefly described the skulls of 

 "the iguanoid lizards allied to Iguana." Except for the recognition of Metopoceros and the 

 omission of Cachryx, the genera included in this discussion were the same as Cope's 

 (1886) Iguaninae. Dipsosaurus and Sauromalus were again left out of the group. 



Cope later (1900) greatly expanded his Iguaninae, and named two additional iguanid 

 subfamilies, Anolinae and Basiliscinae. This new Iguaninae was a catch-all group for 

 those iguanids that lacked midventrally continuous postxiphistemal inscriptional ribs, had 

 simple clavicles, and lacked a left hepatopulmonary mesentery— in other words, those 

 iguanids that lacked the distinctive features of anolines and basiliscines. Although this new 

 Iguaninae was almost certainly an unnatural group, Cope recognized a slightly expanded 

 version of his earlier (1886) Iguaninae as a discrete subset of his new and more inclusive 

 group of the same name. This unnamed subset was characterized by the presence of 

 femoral pores and of vertebrae with zygosphenal articulations. It contained Dipsosaurus 

 and Sauromalus along with the genera included in his earlier Iguaninae; and it is therefore 

 identical in generic content to the iguanine group as currently conceived. 



The Twentieth Century. During the first three-fourths of the twentieth century, the 

 concept of an iguanine group underwent considerable change. The efforts of nineteenth- 

 century authors such as Cope and Boulenger seem to have been largely ignored, and at 

 least two authors envisioned the ancestry of most other North American iguanids within 

 iguanines. This idea seems to have resulted from the misconception that iguanines were 

 "primitive" iguanids and were, therefore, potential ancestors of other iguanid taxa; the 

 integrity of the group was deemphasized or completely overlooked. Nevertheless, by the 



