33^ 



REPTILIA 



Ornithopoda, had a bird-like beak, and the Orthopoda had pneumatic 

 bones and a bird-like pubis. 



Order 4. Crocodilia. — Fossil Crocodilia are found in the Triassic 

 strata. Huxley traced an " almost unbroken series " of Crocodilia 

 from the Triassic down. 



Order 5. Pterodactyla or Pterosauria. (Gr. pteron, a wing; and 

 sauros, a lizard.) — The Pterosauria were adapted for flight, having 

 a long neck and a pair of bat-like leathery wings. The bones were 

 light and hollow, the breast bone was keeled. The earlier forms had 

 sharp teeth. They varied in size from that of a sparrow to the 

 Pterodactyl with a twenty-four foot wing stretch. The largest 

 forms lacked teeth and had a short tail. 



Order 6. Squamata. — The Squamata are geologically the most 

 recent of the Reptilia now persistent. 



Sub-Order {a). Lacertilia. — There are a few fossil lizards in the 

 Jurassic, but the majority began with the Tertiary. 



Sub-Order {b). Ophidia. — Fossil snakes appeared in the Ter- 

 tiary strata. 



Sub-Order (c). Pythonomorpha. — These extinct forms had a 

 snake-like body with paddle-like limbs used in swimming. They 

 reached a length of over fifty feet {Mososaurus). The skull re- 

 sembled that of the Lacertilia. 



Adaptations of Reptilia. — The Crocodilia have protective bony 

 plates in the skin, sharp teeth, strong jaws and a muscular tail. A 

 valve in the throat shutting off the mouth from the pharynx (see p. 

 326) enables them to submerge their prey and still breathe with 

 ease. The Chelonia have a strong compact box-like shell and 

 powerful cutting jaws. Large lungs enable them to remain under 

 water for some time. Lacertilia have rapid locomotion. In some 

 protective coloration is evident. The long tail is a storehouse for 

 food and in many species is broken off and left when enemies are 

 pressing. Ophidia have displaceable jaw bones and loose ribs, 

 permitting the animal to swallow prey larger than itself. The 

 glottis is anterior to the mouth, enabling the snakes to breathe while 

 swallowing. The teeth are recurved so that the prey cannot escape. 

 Snakes kill by crushing or utilizing poison glands. 



Economic Importance of Reptilia. — Crocodilia furnish skins that 

 are used in the manufacture of shoes, bags, pocket books and belts. 

 They feed on fish and in the case of the Asiatic and African crocodiles, 

 destroy many human lives. The flesh of crocodiles is said to be 



