512 



ZOOLOGY. 



The Ichtliyosaurs were colossal reptiles from two to thirteen 

 metres (six to forty feet) in length, swimming in the ocean by 

 four paddle-like limbs consisting of six rows of digital bones 



Fig. 448. Skull of Ichthyosaurus ; lateral view. Pmx, premaxillary bone ; 3/ar, 

 maxillary ; N, nasal ; Fr, frontal ; Prf, prefrontal ; Pof, postfrontal ; Pa, parietal 

 //, lachrymal ; M. raalar ; Qj, quadratojugal ; Q, quadrate; Pob, poetorbital ; Sg>. 

 equaniosal ; D. dentary ; Ang, angular ; Art, articular ; S. Ar, subarticular ; Pttr 

 pterygoid. After Cope. 



the head was very large, the neck very short, and the orbits. 



were enormous ; the vertebrae were remarkably short and bi- 



concave. They were carniv- 

 orous, and powerful swim- 

 mers, and common in the Ju- 

 rassic seas of Europe ; one- 

 form existed in the Jurassia 

 times in Wyoming. 



Order 7. Theromorplia. 

 This order is divided into the- 

 Pelycosauria and Anomo- 

 dontia. The beaked Saurians 

 were somewhat lizard-like, but 

 ri?. 4i9.-post"rior view of the >-kii]i of were synthetic types, combin- 



IchthyoxauruB ; letterin;,' as in Fig 443, . , , i ,. , i T i 



with lollowins; additions ; Bo, basiocci- mg the Characters OI the icll- 



pital : EJ-O, Exocc-ipital ; Sup. 0. nupra- ., ,-, Ll ,, 



occipital ; 0/)0, opisthotic ; St<i/i, supra- thVOSaill'S, tllO turtles, the 

 b,,lar.-After Cope, with thoge of Hz . 



ards, Dinosaurians, and crocodiles. The skull was short, 

 and in Dicynodon the jaws in front had the nipping, horny 

 beak of a turtle, while from behind in the upper jaw pro- 

 truded two long, curved, canine teeth. Dicynodon tiyricepx 

 Owen, had a skull about half a metre (20 inches) long.. 



