THE WEALDEN STRATA 21 



some idea of the sort of beast the Iguanodon was. I 

 should tell you why he was so named. Before it was 

 known what he was like in general form, it was found that 

 his teeth, which are of a remarkable character, were 

 similar to those of the Iguana, a little lizard of the West 

 Indies. So he was called Iguanodon, an animal with 

 teeth like the Iguana (fr. Iguana, and Gk. o$wr g. dSovros- 

 a tooth). He was quite a harmless beast, though he was 

 so large. He was a vegetarian. There were other great 

 reptiles, more or less like him, which were also vegetable 

 feeders. But there were also carnivorous reptiles, 

 generally smaller than the herbivorous, whose teeth tell 

 us that they preyed on other animals. 



Those were the days of reptiles. Now the earth is the 

 domain of the mammalia. But then great reptiles like 

 the Iguanodon wandered over the land ; great marine 

 reptiles, such as the Plesiosaurus, swam the waters ; and 

 wonderful flying reptiles, the Pterodactyls, flew the air. 

 Some species of these were quite small, the size of a rook : 

 one large species found in the Isle of Wight had a spread 

 of wing of 16 feet. Imagine this strange world, its 

 forests with pines and monkey puzzles and cycads, ferns 

 also, of which many fragments are found, its great 

 reptiles and little reptiles, on land, in the water and the 

 air. Were there no birds? Yes, but they were rare. 

 From remains found in Oolitic strata, somewhat older 

 than the Wealden, we know that birds were already 

 in existence ; and they were as strange as anything else. 

 For they had jaws with teeth like the reptiles. They had 

 not yet adopted the beak. And instead of all the tail 

 feathers starting from one point, as in birds of thv, present 

 day, these ancient birds had long curving tails like reptiles, 

 with a pair of feathers on each joint. Birds of similar but 

 slightly more modern type have been found in Cretaceous 

 strata (to which the Wealden belongs) in America, but so 

 far not in strata of this age in Britain. 



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