Phylogenetic Systematics of I guanine Lizards 139 



34-35-A. Anterior inferior alveolar foramen lies between splenial and dentary; 

 coronoid may or may not contribute to its posterior margin. 



36- A. Labial process of coronoid present but relatively small. 



37-A. Angular extends far up lateral surface of mandible and is easily visible in lateral 

 view. 



38-A. Angular wide posteriorly. 



39-A. Surangular does not extend anteriorly to last dentary tooth on labial surface of 

 mandible. 



40- A. Dome-shaped portion of surangular visible below coronoid on lingual surface of 



mandible. 



41 -A. Angular process of prearticular increases substantially in relative size during 

 postembryonic ontogeny, becoming a prominent structure in adults. 



42- A. Outline of retroarticular process triangular rather than quadrangular in all 

 postembryonic developmental stages. 



43-44-B. Mode of seven premaxillary teeth. 



45-A. Lateral cusps of premaxillary teeth small or absent. 



46-A. Posterior marginal teeth tricuspid. The presence of a fourth cusp may be a 

 synapomorphy of all iguanines, with secondary loss in Amblyrhynchus and in some 

 Brachylophus and Ctenosaura. Alternatively, the ancestral iguanine may have been 

 polymorphic for the presence of a fourth cusp (again with secondary loss in 

 Amblyrhynchus and some Ctenosaura). 



41- A. Individual lateral cusps of tricuspid marginal teeth much smaller than apical 

 cusp. 



48- A. Entire pterygoid tooth row lies close to ventromedial edge of pterygoid. 



49-A. Pterygoid tooth patch consists of a single row of teeth throughout 

 postembryonic ontogeny. 



50-A. Pterygoid tooth patch extends anteriorly beyond level of posterior edge of 

 suborbital fenestra. 



51 -A. Pterygoid teeth present. 



52-53-B. Second ceratobranchials from two-thirds length to slightly longer than first 

 ceratobranchials. 



54-A. Second ceratobranchials in medial contact for most or all their lengths. 



55-A. Neural spines of presacral vertebrae tall, more than 50% of total vertebral 

 height. 



56-A. Zygosphenes connected to prezygapophyses by continuous arc of bone. 



57-A. Posterolateral processes present on pleurapophyses of second sacral vertebra. 



58- A. Foramina present in ventral surface of pleurapophyses of second sacral vertebra. 



59-A. More than 40 caudal vertebrae. 



60- A. Caudal autotomy septa present. The polarity of this character is questionable. 



61 -A. Autotomic caudal series (or series of caudal vertebrae with paired transverse 

 processes) begins at or before 10th caudal vertebra. The polarity of this character is 

 questionable. 



