118 HIGH SCHOOL ZOOLOGY. 



saurns liad bony shields in the skin and projecting horns from 

 the back wliiuh must have afforded a very comiilcte defensive 

 armour. Tiiis genus also is iiateresting from the fact that the 

 fore legs were shorter than the hind, and consequently that the 

 latter along with the tail supported tlie weight of the body. A 

 transition is thus afforded to the Ornithopoda or bird-footed 

 Dinosaurs, a remarkable group, of whicli the best known is the 

 genus Iguanodon of the Cretaceous period. (Fig. 87.) Recent 



Fig. 87 — Skeleton of Iguanodon in the Brussels Museum. ^. 

 discoveries in Belgiiim have disclosed complete skeletons of this 

 reptile, which is characterised cliief^y by the strong bird-like 

 three-toed legs, the short fore legs used only for j)rehension, the 

 lizard-like tail and the compressed body. The foot prints of this 

 Iguanodon, which are also preserved, show that its gait was 

 erect, and this is confirmed by examination of the saci'al region 

 of the vertebral column, which is formed of five or six united 

 vertebrae, evidently for the purpose of transfen-ing the weight of 

 the body to the hind legs. The Iguanodon was herbivorous, but 

 there were carnivorous Dinosauria likewise, some like Compso- 

 gnathus (Fig. 88) of such small dimensions that they hardly 



