MESOZOIC AND CENOZOIC LIFE 429 
The amphibians, which began to be important in the 
Carboniferous, decrease during the Mesozoic, and their 
place is taken by reptiles, which have developed into 
extraordinary abundance, variety, and size. In fact, the 
Mesozoic has been called the Age of Reptiles. Immense 
Fic. 247. 
A group of Cretaceous cephalopods. 
(1, Ammonites subradetus ; Belemnites sp. ; 3, Ammonites mammilatus; 4, Ammo- 
nites semicelatus ; 5, Ammonites henleyi; 6, Nautilus semistriatus.) 
land saurians (Dinosaurus, ete. (Fig. 251)), as large as 
our largest mammals, in fact in some cases even larger 
than the elephant, moved sluggishly over the land, 
some feeding upon plants, and even reaching into the 
branches of trees for their food, while others subsisted 
upon their fellow-creatures. In the sea, huge reptiles 
