CHAPTER VII 



A SYNOPTIC CLASSIFICATION OF THE REPTILIA 



ANAPSIDA. Temporal region of skull roofed over, or secondarily 

 emarginated, not perforated. 



1. Cotylosauria. Skeleton primitive; two coracoids"; at least eight- 

 een dorsal vertebrae, their ribs not expanded. 



A. Seymoiiria. Most primitive; teeth conical, in single row; 

 intertemporal and otic notch. Insectivorous. Lower 

 Permian. 



B. DiADECTOSAURiA. Teeth heterodont, the posterior trans- 

 versely molariform, crushing. Malacophagous. Lower 

 Permian. 



C. Labidosauria. Teeth anisodont, in two or more rows pos- 

 teriorly; no supratemporal; interparietal on posterior sur- 

 face. Lower Permian. 



D. LiMNOSCELis. Teeth anisodont, conical, in single row; inter- 

 parietal on dorsal surface. Tail long. Lower Permian. 



[E. Pantylosauria. Teeth blunt or pebble-like, in single rows 

 in upper jaw and dentary, numerous on palate and coro- 

 noid; interparietals large on dorsal surface. Lower Permian.] 



F. Pariasauria. Teeth anisodont, the posterior flattened 

 [compressed] and crenulate; an acromion. Middle and 

 Upper Permian. 



G. Procolophonia. Incisors conical, posterior teeth trans- 

 verse, crushing; no supratemporal; interparietal obsolete 

 or absent. Triassic. 



2. Eunotosauria. Skeleton primitive; two coracoids, ten dorsal 

 vertebrae, their ribs expanded to meet on the dorsum, and a 

 dermal layer of bony plates. Middle Permian. 



3. Testudinata (Chelonia). Skeleton not primitive; a single cora- 

 coid; ten dorsal vertebrae, their ribs expanded to meet on the 

 dorsum or a dermal layer of bony plates. 



A. Amphichelydia. No mesoplastra. Cervical vertebrae am- 

 phicoelous or concavo-convex, neck not retractile. Upper 

 Triassic to Cretaceous. 



B. Pleurodira. Neck retracted laterally; pelvis united with 

 plastron. Jurassic to Recent. 



C. Cryptodira. Neck retracted vertically; carapace with 

 peripheral plates. Jurassic to Recent. 



D. Trionychoidea. Neck retracted vertically; no peripheral 

 plates. River turtles. Cretaceous to Recent. 



1 [But see footnote on page 126. — Ed,] 



