PHRYNOCEPHALUS PHYLOGENY 



Fig. 8 Left side of head showing differences in number of horizontal rows of scales immediately above the supralabials counted below the anterior eye, 

 and in the size of the subocular and anterior temporal scales, a. 2 or 3 rows above supralabials, subocular and one or more anterior temporals enalarged 

 and elongate (P. clarkorum); b. 4—5 rows above supralabials, suboculars and anterior temporals not enlarged (P. golubevi). 



Fig. 9 Ventral views of underside of head showing differences in scalation. a. Scaling more or less uniform (P. arabicus). b. Scaling heterogeneous, with 

 curved lateral row of enlarged scales, a large central patch of enlarged pointed scales, and scales at sides of throat, behind level of angle of mouth, very 

 small and granular (P. euptilopus). 



19. Single internasal scale with a vertical keel. No (0); yes (1). 



20. Number of horizontal rows of scales immediately above the 

 supralabials, counted below anterior part of eye (Figure 8). 

 Usually three rows, occasionally two (0); usually four or even 

 five rows (1). 



21. Enlarged subocular scales (Figure 8). Not or only weakly 

 differentiated (0); one or more enlarged, keeled, antero- 

 posteriorly elongated scales (1). 



22. One or more enlarged, diagonally keeled and elongated scales 

 on anterior temporal region (Figure 8). No (0); yes (0). 



23. External ear opening. Present (0); absent (1). 



24. A lateral row of enlarged throat scales beginning in mental area 

 and curving backwards and outwards usually to the vicinity of 

 the angle of mouth, separatedfrom lower labial scales anteriorly 

 by one to three rows of scales (Figure 9). No (0); yes (1). 



25. Enlarged scales in curved lateral row on throat keeled. No (0); 

 yes(l). 



26. A large central patch of enlarged pointed scales on throat, the 

 more postero-lateral ones directed outwards and backwards 

 (Figure 9). No (0); yes (1). 



27. Scales at sides of throat, behind level of angle of mouth very 

 small and granular (Figure 9). No (0); yes (1). 



28. Some scales on posterior temporal region and on sides of 

 anterior neck enlarged, elongate and pointed, and directed 

 outwards and upwards. No (0); yes (1). 



29. Distinct enlarged, raised, often pointed tubercles on dorsum of 

 body. No(0);yes(l). 



Tubercles are enlarged scales that project markedly above 

 the general level of the dorsal body skin. They may be sex- 

 ually dimorphic in Phrynocephalus, often being more strongly 



