148 EXTINCT MONSTERS 



localities where the animal had evidently become mired, just as 

 cattle at the present day sometimes become hopelessly fixed in a 

 swampy place on the margin of a lake or river (see p. 19). Each 

 track made by the creature in walking occupied one square yard 

 in extent ! 



The Sauropoda, or lizard-footed Dinosaurs, show in many ways 

 a decided approach to a simple or generalised crocodile ; so much 

 so, that Professor Cope is inclined to include crocodiles and sauro- 

 podous Dinosaurs in the same order. Vertebra, limb-bones, 

 skulls, and teeth have all been discovered through the zeal and 

 energy of Professor Marsh and his comrades, in the far west of 

 America, as well as by the researches of English geologists, assisted 

 by the labours of many ardent collectors of fossils, in this country. 

 Some of these may now be briefly considered. 



^ 



In Plate XVIII. we have endeavoured to give some idea of a 

 huge thigh-bone (femur) belonging to the truly gigantic Dinosaur 

 called Atlantosaurus. It is six feet two inches long, and a cast 

 of it may be seen in the fossil reptile gallery of the British 

 Museum of Natural History. It should be mentioned, however, 

 that the original specimen is partly restored, so that its exact 

 length to an inch or so is not quite certain. In our illustration 

 it is shown to be a little taller, when placed upright, than a full- 

 grown man. Professor Marsh, the fortunate discoverer of this 

 wonderful bone, calculates that the Atlantosaurus must have 

 attained a length of over eighty feet ! and, assuming that it 

 walked upon its hind feet, a height of thirty feet ! 



It doubtless fed upon the luxuriant foliage of the sub-tropical 

 forests, portions of which are preserved with its remains. Besides 

 this thigh-bone, Professor Marsh has procured specimens of 

 vertebrae from the different parts of the vertebral column ; but no 

 skull or teeth. The vertebrae are hollowed out much in the same 



