Phylogenetic Systematics oflguanine Lizards 



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FIG. 57. Geographic distribution of Amblyrhynchina (Amblyrhynchus and Conolophus). 



Distribution: Islands of the Galapagos Archipelago, Ecuador (Fig. 57). 



Diagnosis: Members of this taxon can be distinguished from other iguanines by the 

 following synapomorphies: 



1. Nasal process of premaxilla covered dorsally between nasals (5-B). 



2. Prefrontal contacts jugal, and lacrimal fails to contact palatine behind lacrimal 

 foramen (7-B). This character occurs also in some Ctenosaura (clarki) and Cyclura 

 (carinata, cornuta, and ricordii), in which it is interpreted as at least two separate instances 

 of convergence with the condition seen in Amblyrhynchina. 



3. Frontal wider than long (8-B). This character occurs also in Cyclura cornuta and 

 Iguana delicatissima, which I interpret as two separate instances of convergence. 



4. Lacrimal relatively small (17-B,-C). 



5. Dorsal surface of vomerine process of palatine bears a high medial crest (21-B). 



6. Labial process of coronoid relatively large (36-B,-C). This character occurs also in 

 Brachylophus, in which it is interpreted as convergent. 



7. Angular does not extend up lateral surface of mandible and is barely visible in lateral 

 view (37-B). This character also occurs in Sauromalus and is either convergent or a 

 synapomorphy of a more inclusive taxon. 



