190 WHEN THE WORLD WAS YOUNG 



unearthed at Swindon, but are found far more fre- 

 quently in the Rocky Mountains. It is, perhaps, quite 

 the most curious in shape of all these strange old animals. 

 Its body forms an arch, with a pair of long solid legs not 

 far from the centre, and another pair of quite little ones 

 near its small head. Right down the middle of its back, 

 stretching from its head to its spiny tail, was a ridge of 

 huge bony plates, like colossal ivy leaves, the centre ones 

 measuring two or three feet across. It seems to have been 

 about twenty-five or thirty feet long ; its sense of smell was 

 very acute, its eyes were large, and could absorb much light, ' 

 and it ought to have been very clever, as it had two sets 

 of brains, one in the usual place, and the other, ten times 

 bigger, near the thigh. As may be imagined, the 

 Stegosaurus (or ' lizard with a roof ') was very heavy to 

 move, and most likely found it pleasanter to pass most of 

 its time in the water, which, being of more weight than 

 the air, would support its great bones better. But when 

 on land it could defend itself from its enemies by the help 

 of its tail, which had four pairs of strong sharp spikes, 

 calculated to keep the most bloodthirsty animal at bay. 

 Its own food, as shown by its teeth, was soft juicy plants. 



There is no time to say much of the largest of all 

 the Dinosaurs, which has been found in America, and 

 measured more than eighty feet. Its thigh bone alone 

 was taller than a man, and if it walked upright it would 

 certainly have been thirty feet high. Nor can we linger 

 over the fish lizards, which came before all these, or the 

 lobster-like creatures that lived before them, or over the 

 crocodiles, some eighteen feet long, found in the new 

 red sandstone and later rocks, or over the tapirs, or 

 many more. But we must just glance at a few birds 

 which are now extinct, partly through the merciless 

 hunting down by man, and partly owing to natural 

 causes, with which he has nothing to do. 



As far as can be gathered from the rocks, the birds 

 (which did not come into being till the great order of 



