82 The Bad'land Formations of the Black Hills Region 



tooth cats, and while Dinictis, Figure 13, seems to have reached 



Figure 13— Restored Skeleton of Dinictis squalidens. After Matthew, 

 1901. 



as high a stage of specialization as Hoplophoneus, it was evident- 

 ly fitted to a somewhat different life. 



The dentition varies in the different species, the number 

 of teeth ranging from twenty-eight to thirty-four. All have 

 three incisors and one canine on each side, both above and below. 

 The pre-molars vary from two to three, but the molars are fairly 

 constantly one. Only Dinictis felina has two on each side be- 

 low. 



An important feature of the lower jaw is the extreme down- 

 ward projection of its anterior portion. This seems to be a co- 

 incident feature necessitated by the unprecedented development 

 of the powerful canine teeth already mentioned. These upper 

 canine teeth curve forward and downward nearly parallel with 

 each other, and passing* behind the much smaller lower canines, 

 continue approximately to the lowest portion of the anterior 

 downward prolongation of the chin. In general they are later- 

 ally compressed and the edges are more or less serrulated. 

 They are implanted by a strong fang and reach two and one- 

 half or three inches in length. 



The cause of the development of the abnormally powerful 

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

 the cause of much speculation. Matthew in discussing this 

 shows that 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, enabling 

 the animal to strike downward with its saber teeth with enor- 



