PTEROSADRLA. 



S8S 



sternum has a keel and there is no clavicle. The skull is rounded and 

 bird- like. The occipital condyle is single and on the base of the skull. 

 The cranial bones ankylose early as in birds, the orbits are large and with 



Fia. 215. — Dimorphodon maeronyz restoration x}, L. Lias (after Owen, from Woodward) 

 a antorbital tossa ; n external nares ; o orbit. 



sclerotic plates, and there is a wide antorbital fossa as in Aves and Dino- 

 savu-ia. There is a postfrontal, and both upper and lower temporal arcades 

 are present. Teeth are frequently present (on the margins of the jaws only). 



