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104 ANIMALS OF THE PAST 



this weight of skull and body requires very 

 massive legs, and as the fore legs are very 

 short, this enables Trieeratops to browse com- 

 fortably from the ground by merely lowering 

 the front of the head. 



These forms we have been considering were 

 the giants of the group, but a commoner spe- 

 cies, Thespesius, though less in bulk than those 

 just mentioned, was still of goodly proportions, 

 for, as he stalked about, the top of his head 

 was twelve feet from the ground. 



Thespesius and his kin seem to have been 

 comparatively abundant, for they have a wide 

 distribution, and many specimens, some almost 

 perfect, have been discovered in this country 

 and abroad. No less than twenty-nine Igu- 

 anodons, a European relative of Thespesius, 

 were found in one spot in mining for coal at 

 Bernissart, Belgium. Here, during long years 

 of Cretaceous time, a river slowly cut its way 

 tlu'ough the coal-bearing strata to a depth of 

 750 feet, a depth almost twice as great as 

 the deepest part of the gorge of Niagara, 

 and then, this being accomplislied, began the 

 work of filling up the valley it had excavated. 



