204 THE WORLD OF LIFE CHAP. 



As an illustration of how these huge but rather weak 

 vegetable feeders were protected, the restoration of one of 

 them as shown on the opposite page (Fig. 55), may be 

 useful ; especially when we remember that the species 

 figured was as bulky as a rhinoceros or elephant. It was 

 found in the Upper Jurassic strata of North America. 



We now come to some of the largest land- animals 

 which ever lived upon the earth the Sauropoda, or lizard- 

 footed Dinosaurs and these were more or less amphibious. 

 The skeleton of one of these, the Brontosaurus, is shown 

 on page 205 (Fig. 56). It is said to have the smallest 

 head in proportion to the body of any vertebrate 

 animal. Professor O. C. Marsh, who discovered it, states 

 that the entire skull is less in diameter or weight than 

 the fourth or fifth neck vertebra, while the brain-cavity is 

 excessively small. He says : " The very small head and 

 brain indicate a stupid slow-moving reptile. The beast was 

 wholly without defensive or offensive weapons or dermal 

 armour. In habits it was more or less amphibious, and its 

 remains are usually found in localities where the animals had 

 evidently become mired." 



A creature nearly as large was the Cetiosaurus leedsi, 

 from the Oxford clay near Peterborough, of which the left 

 hind limb and the larger part of the tail are mounted in the 

 British Museum. It measures 10 feet 6 inches high at the 

 hip, and must have been nearly 60 feet long. Still larger 

 was the American Atlantosaurus immanis, of which only 

 fragmentary portions have been obtained ; but a complete 

 thigh-bone, 6 feet 2 inches long, is the largest yet dis- 

 covered. It was found in the Upper Jurassic strata of 

 Colorado, U.S.A. 



The largest complete skeleton is that of the Diplodocus 

 carnegit, now well known to all who have recently visited 

 the British Natural History Museum, where a model of it is 

 mounted, as shown in the photograph of it here reproduced 

 (Fig. 57) facing page 205. It is 80 feet in length, both 

 neck and tail being enormously long in proportion to the 

 body. It is supposed that it would have been unable to 

 walk on land except very slowly, and that it must have lived 



