SOUTH DAKOTA SCHOOL OF MINES 



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The cause of the development of the abnormally power- 

 ful upper canines and the uses to which they were put have 

 been the cause of much speculation. (Plates 11 and 12.) 

 W. D. Matthew of the American Museum of Natural His- 

 tory in discussing this indicates that in his opinion there 

 is definite evidence of the adaptation of the canines to 

 a particular method of attack. The head is so shaped 

 that good attachment is allowed for strong muscles, en- 

 abling the animal to strike downward, with its saber teeth 

 with enormous power and the changes in the cranial por- 



Figure 30 — Dorsal view of the fore foot and the hind foot of Hop- 

 lophoneus primaevus. Adams 1896. 



tion allowing for the attachment for the increasingly pow- 

 erful muscles were in strict correlation with the develop- 

 ment of the saber-teeth. Along with these changes was 

 the degeneration and change in shape of the lower jaw, 

 allowing the mouth to be opened to an unusual extent so as 

 to give greatest freedom to the saber-teeth in stabbing the 

 prey. Hoplophoneus in addition to his terrible teeth had a 

 strong body, stout neck and legs and highly developed strong 

 retractile claws. His food must have been in large measure 

 the thick skinned rhinoceroses, elotheres, oreodonts, and 

 other similar animals of the time. The lighter proportioned 



