Phylogenetic Systematics of I guanine Lizards 1 55 



Node 4: Enyaliosaurus Gvd.y \M5 



1. Lateral edges of parietal roof fail to meet, or meet and fail to form a midsagittal crest; 

 outline of parietal roof trapezoidal or triangular (7-B). 



2. Scales on anterodorsal surface of shank enlarged and spinous (15-1 or-2). 



Node 5 (unnamed) 



1. Pendulous dewlap present (10-1 or-2), 



2. Dorsal crest scales unicolored and differing in color from adjacent body scales; 

 large, flap-like crest scales separated by one or more smaller scales (12-1). 



Ctenosaura baked 



1. Crowns of posterior marginal teeth with a maximum of three cusps (9-1). This 

 character occurs also in C. quinquecarinata, where it is interpreted as convergent. 



In some: anterior whorls of strongly spinous caudal scales always separated by at least 

 two rows of smaller scales (18-0). This is interpreted as a case of character reversal. 



Ctenosaura palearis 



1. Large pendulous dewlap present (10-2). 



2. All anterior whorls of strongly spinous caudal scales (except sometimes the first) 

 separated by one or no intercalary scale rows (18-2 or-3). This character occurs also in C. 

 defensor, C. clarki, and C. quinquecarinata, in which it is interpreted as convergent; 

 altematively, it may be a synapomorphy of a more inclusive group (Enyaliosaurus). 



Node 6 (unnamed) 



1. Maximum snout- vent length less than 190 mm (1-1). 



2. Mode of 25 presacral vertebrae (2-1). 



3. All anterior whorls (except sometimes the first) of strongly spinous caudal scales 

 separated by one or no intercalary scale rows (18-2 or 3). This character occurs also in C. 

 palearis, where it is interpreted as convergent; altematively, it may be a synapomorphy of a 

 more inclusive group. 



The occurrence of five premaxillary teeth in at least some specimens, as well as 

 enlargement of the scales on the anterodorsal surface of the thigh, may also be 

 synapomorphies of this group. 



Ctenosaura quinquecarinata 



1. Crowns of posterior marginal teeth with a maximum of three cusps (9-1). This 

 character occurs also in C bakeri, in which it is interpreted as convergent. 



In some: prefrontal contacts jugal behind lacrimal foramen (4-B). This character 

 occurs also in C. clarki, in which it is interpreted as convergent. 



