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University of California Publications in Zoology 



B 



-^ /®p 



aip 



FIG. 41. Pelvic girdles of (A) Sauromalus obesus (RE 467) and (B) Ctenosaura pectinata (RE 419) in 

 dorsal view. Scale equals 1 cm. Abbreviations: aip, anterior iliac process; ep, epipubis; hi, hypoischiac 

 cartilage; il, ilium; is, ischium; it, ischial tuberosity; pi, proischiac cartilage; pu, pubis. 



another, yielding a diamond-shaped sternum (Fig. 40B). In Sauromalus the xiphistema are 

 widely separated from one another, and the sternum is pentagonal (Fig. 40C). 

 Amblyrhynchus is somewhat intermediate, having a small but distinct gap between its 

 xiphistema; however, the shape of its sternum is much closer to that of most other 

 iguanines than to that of Sauromalus. 



Most members of all outgroup taxa examined have diamond-shaped sterna with the 

 xiphistema in close proximity to each other. The exceptions are Oplurus quadrimaculatus 

 and Crotaphytus, which approach the condition seen in Sauromalus to a greater or lesser 

 degree, respectively. Although the pentagonal stemum with widely separated xiphistema is 

 probably apomorphic, the ambiguity is sufficient to force me to use this character only at a 

 less inclusive level than that of all iguanines. 



PELVIC GIRDLE 



The iguanine pelvic girdle (Fig. 41) consists of three pairs of bones: dorsal ilia, which 

 articulate with the sacral pleurapophyses; posteroventral ischia; and anteroventral pubes. 

 Cartilaginous epipubes, and proischiac and hypoischiac cartilages, are situated on the 

 midline between the pubes and the anterior and posterior parts of the ischia, respectively. 

 An obvious difference in the shape of the pelvic girdle separates Sauromalus (Fig. 41 A) 

 from all other iguanines (Fig. 4 IB). Relative to those of other iguanines, the pelvis of 

 Sauromalus is short and broad, clearly an apomorphic condition on the basis of the 

 outgroups examined. 



