E.N. ARNOLD 



Fig. 1 Anterior views of right nasal area of skulls showing differences in contribution of the maxilla (m) to the posterior wall of the narial opening, 

 a. Small, does not contact septomaxilla (s) (Bufoniceps laugwalaensis). b. More extensive contribution, especially dorsally, and broad contact with 

 septomaxilla (Phrynocephalus mystaceus). c. More extensive still, both dorsally and ventrally, broad contact with septomaxilla maintained (P. 

 euptilopus). 



y\r 



Fig. 2 Anterior views of right nasal area of skulls, a. Dorsal process of maxilla (m) tapering upwards, maxilla extending outwards below lateral process of 

 prefrontal bone (pf) which is large (P. euptilopus). b. Dorsal process of maxilla blunt above, maxilla not extending markedly outwards below lateral 

 process of premaxilla which is relatively small (P. persicus). 



forms that Moody allocated to Stellio (Schatti & Gasperetti, 1994; 

 Henle, 1995; Baig & Bohme, 1997). 



Unweighted Wagner tree analysis of the morphological data 

 presented by Moody (1980) indicated that Phrynocephalus was 

 derived from a paraphyletic Agama s. str., while compatability 

 analysis, and Wagner tree analysis where characters were weighted 

 according to their consistency index in an initial run, suggested that 

 Phrynocephalus was sister to all other members of Moody's Group 

 6 (Moody, 1980). 



Results of isozyme analysis have been interpreted as indicating 

 that Phrynocephalus is the sister group of Laudakia (Ananjeva & 

 Sokolova, 1990), a result in agreement with immunological studies 

 (Joger, 1991). In contrast, a reassessment of morphology (pers. obs.) 

 suggests that the sister group of Phrynocephalus + Bufoniceps is 

 Trapelus. Shared features that appear derived within Moody's Group 

 6 include the following: maxillae in contact beneath premaxilla, 

 lateral prefrontal processes very large, palatine roof of interorbital 

 canal narrow or absent, vomers fused, squamosal spatulate with no 

 hook-shaped projection on its lateral margin, presacral vertebrae 

 usually 22 or fewer; nostrils directed forwards rather than sideways, 

 no enlarged subocular scales (reversed in some Phrynocephalus), 

 external ear opening reduced in size, no spinous scales on dorsum of 



neck (reversed in some Phryncocephalus), no caudal autotomy. 

 scales on tail not in regular whorls; nasal passage long and flexed, 

 depressor mandibulae muscle extends partly over tympanum. 



MORPHOLOGICAL CHARACTERS USED TO 

 ESTIMATE PHYLOGENY 



Skull 



1 . Contribution of the maxilla to the posterior wall of the narial 

 opening of the skull (Figure 1). Small, does not contact 

 septomaxilla (0); more extensive especially dorsally, broad con- 

 tact with septomaxilla ( 1 ); more extensive still both dorsally and 

 ventrally, broad contact with septomaxilla maintained (2). 



2. Dorsal process of maxilla (Figure 2). Tapering upwards (0); 

 broad and ending bluntly above (1). 



3 . Maxilla extends clearly outwards below the anterior surface of the 

 lateral process of the prefrontal bone (Figure 2). No (0); yes (1). 



4. Relationship of maxillary and nasal bones below the lateral 

 process of the nasal (Figure 3). Widely separated (0); more 

 narrowly separated (1); in contact (2). 



