THE BRONTOSAUR AND ITS COUSINS 63 



luscious vegetation that abounded. The Brontosaur 

 was quite a modest member of the family. He 

 weighed only about twenty tons when he was fully 

 grown! But as his length was only sixty feet, the 

 Diplodocus (eighty feet) must have been much 

 heavier; and we now know, from bones we have 

 found in America, that some of these Deinosaurs 

 were about twice as long as the Diplodocus, or a 

 hundred and sixty feet long. 



Another branch of the family were leaping reptiles. 

 Some stood only about two feet high, when they were 

 erect, and others thirty or forty feet. There were 

 some with hollow bones, like birds, so that we must 

 not allow the lazy monsters of the swamp to mislead 

 us. The new ''Golden Age" was not long an age of 

 tranquillity and mere feeding. The inevitable struggle 

 for life began. At all periods in the history of the 

 earth part of a family has been apt to turn carnivorous 

 and prey upon its fellows, and the skeletons and teeth 

 of the great reptiles show that this terrible struggle 

 set in in the Mesozoic Age. Teeth grow larger and 

 more numerous and more carnivorous, until at last 

 we get appalling fiesh-eating monsters with two or 

 three hundred formidable teeth in their jaws. 



Armour, as is usual, keeps pace with the develop- 

 ment of teeth. Ponderous and sluggish vegetarians, 

 forty feet long, developed rows of great plates of bone 

 standing upward from their backbones. Others had 

 massive coats of horn over their heads and necks, 



