U. S. GEOLOGICAL SURVEY 



BULLETIN 612 PLATE V 



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A. SKELETON OF THE HEAD OF HESPERORNIS. 

 A large diving bird having teeth, which were probably used in catching and holding fish on which it fed. 



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J?. RESTORATION OF A MOSASAUR (TYLOSAURUS), 



A sea monster about 30 feet long. (After Hutchinson.) 



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a RESTORATION OF A PTERODACTYL (ORNITHOSTOMA). 

 A flying dragon measuring 1 8 feet from tip to tip of wings. (After Lucas.) 



ANIMALS THAT LIVED IN CENTRAL NORTH AMERICA IN CRETACEOUS 



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