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. 



FlG. 300. Pareiasaurus 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 vertebrae ; 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; /;/, infranasal ; /, jugal ; /, lachrymal; mx, maxilla; n, nasal; o, orbit; 

 P, parietal; />/, postfrontal ; //, palatine; ////, premaxilla; /;-, prefrontal ; //, 

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



