SYSTEMATIC CHARACTERS 



Based on the descriptions of the iguanine skeleton and other anatomical features given 

 above, I recognize the following systematic characters for use in phylogenetic analysis. 



SKELETAL CHARACTERS 



L Ventral surface of premaxilla (Fig. 7): (A) bears large posterolateral processes; (B) 

 posterolateral processes absent. 



2. Posteroventral crests of premaxilla (Fig. 7): (A) small, do not continue up the sides 

 of incisive process and are not pierced by foramina for maxillary arteries; (B) large, 

 continue up sides of incisive process and are pierced or notched by foramina for maxillary 

 arteries. 



3. Anterior surface of rostral body of premaxilla: (A) broadly convex; (B) nearly flat. 



4. Nasal process of premaxilla I (Figs. 6, 14, 45): (A) slopes backwards; (B) nearly 

 vertical. 



5. Nasal process of premaxilla II (Fig. 8): (A) wholly or partly exposed dorsally 

 between nasals; (B) covered dorsally between nasals. 



6. Size of nasals and nasal capsule (Figs. 5, 9, 11): (A) nasal capsule of moderate 

 size, nasals relatively small; (B) nasal capsule enlarged, nasals relatively large. 



7. Bones in anterior orbital region (Fig. 10): (A) lacrimal contacts palatine behind 

 lacrimal foramen; (B) prefrontal contacts jugal behind lacrimal foramen. 



8. Frontal (Figs. 5, 9, 11): (A) longer than wide, or length approximately equal to 

 width; (B) wider than long. 



9. Large paired openings at or near frontonasal suture: (A) absent; (B) present. 



10. Cristae cranii on ventral surface of frontal (Fig. 12): (A) extend in a smooth 

 continuous curve from frontal onto prefrontals; (B) frontal portions project anteriorly, 

 forming a step between frontal and prefrontal portions. 



11. Paired cristae on ventral surface of frontal medial to cristae cranii (Fig. 12): (A) 

 absent or weakly developed; (B) strongly developed, united as a single median crest 

 anteriorly and together with the cristae cranii forming pockets in the anteroventral surface of 

 the frontal. 



12. Dorsal borders of orbits (Figs. 5, 9, 11): (A) more or less smoothly curved; (B) 

 wedge-shaped. 



13. Position of parietal foramen (Figs. 5, 9, 11; Table 2): (A) on the frontoparietal 

 suture; (B) variable (either A or C); or (C) within the frontal bone. 



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