REPTILES. 



305 



Texas ; Elginia, triassic of Scotland. Isodectes, from the coal of Ohio, is 

 the oldest known reptile. This sub-order is regarded by Cope as ancestral 

 to all other reptiles. 



FIG. 300. Pareiasatirus baini, after Seeley. 



SUB-ORDER 2. ANOMODONTIA. 



Large lizard-like, five-toed reptiles ; toothless, or with a single pair of 

 canine-like teeth ; no intercentra ; five or six sacral vertebras ; a single 

 occipital condyle ; supratemporal fossa present. Dicynodon and Ouden- 

 odon, South African Permo-trias. 



FIG. 301. Skull of Dicynodon, after Seeley. bo, basioccipital ; c, columella; 

 f, frontal ; in, infranasal ; /, jugal ; /, lachrymal ; nix, maxilla ; n, nasal ; o, orbit ; 

 /, parietal; //, postfrontal ; //, palatine; pm, premaxilla; pr, prefrontal; pt, 

 pterygoid ; q, quadrate ; s, squamosal ; /, temporal fossa ; v, vomer. 



