762 GEOLOGY 



The Land Animals 



The terrestrial animals had the same general aspect as in the 

 preceding period. In Europe, where the sea made great inroads 

 upon the land, there was some decline in their abundance, variety 

 and proportions; but in America, the area of land was not small 

 enough to restrain greatly the evolution of the reptiles. On both 

 continents the aquatic reptiles seem to have made greater pro,n 

 than the terrestrial forms. 



The dinosaurs still retained the leading place among the land 

 reptiles, though the carnivorous forms (Theropoda) were less abun- 

 dant and varied than before. Among them was a leaping, kangan >< - 

 like form (Lcelaps-or Dryptosaurus) with a length of 15 feet. The 

 most singular dinosaurian development was among the herbivorous 

 branch, some of which were very large, of quadrupedal habit, with 

 enormous skulls which extended backwards over the neck and 

 shoulders in a cape-like flange (Fig. 514) . Added to this was a sharp, 

 parrot-like beak, a stout horn on the nose, a pair of large pointed 

 horns on the top of the head, and a row of projections around the 

 edge of the cape. One of the larger skulls measures eight feet 

 from the snout to edge of the cape. This excessive provision for 

 defense was not unnaturally accompanied by evidences of low 

 mentality, in the form of a very small brain cavity. Marsh remarks 

 that they had the largest heads and the smallest brains of the rep- 

 tile race. They were doubtless stupid and sluggish. The omit h- 

 opod division was well represented (Fig. 516). Their posterior 

 parts were strongly developed, their limbs were hollow, and 

 their footprints indicate that they walked in kangaroo-like at tit ude. 

 Save for the thalattosaurs, some of the dinosaurs (of the Niobrara) 

 were among the first distinctively American air-lnvathin^ forms 

 since the Permian. 



Distinctively terrestrial lurile remains are found in the Dakota 

 sandstone, and the fossils of species inhabiting fresh waters 1 

 been found in the late Cretaceous (Belly River) deposits of Canada. 

 Of true lizards, which appeared in the Triassic, only one later M< 

 zoic form is known, and that of small size and uncertain aflinities 

 from the Laramie. Snakes made their first appearance, so far 



