538 LAND MAMMALS IN THE WESTERN HEMISPHERE 



retractile and as fully hooded as in any of the subsequent 

 genera. 



That fHoplophoneus was a fierce destroyer, is made evident 

 by every part of its skeleton, and, like other cats, it no doubt 

 subsisted upon warm-blooded animals, which it killed for itself, 

 the size of the prey being determined by the size and power of 

 the particular species of the fsabre-toothed genus. In view of 

 the probable extent of the Oligocene forests, the restoration 

 (Fig. 264) gives the animal a spotted coat and the general 

 aspect is that of one of the modern spotted cats, but the pro- 

 truding ends of the tusks and the relatively long head distin- 

 guish it from any existing cat. ''The presence of long, 

 knife-like canines is correlated with powerful grasping feet 

 possessing highly developed retractile claws. With its power- 

 ful feet the animal clung to its prey, while it struck repeatedly 

 with its thin, sharp sabres " (J. C. Merriam), 



In the latter part of the White River stage lived one of the 

 most highly specialized of the fmachairodonts, so far, at least, 

 as the dentition is concerned, for only the skull is known. 

 This genus, fEusmilus, which also occurred in the Oligocene 

 of Europe, was apparently an example of premature specializa- 

 tion which led to nothing, for none of the subsequent genera 

 could have been derived from it. The teeth were reduced to 

 a minimum in number : i | , c |, p f , w y, X 2 = 24, one lower 

 incisor and at least one premolar less in each jaw than had 

 '\Hoplophoneus. The canine tusk was very large and the 

 flange of the lower jaw for its protection correspondingly 

 elongated, being more prominent than in any other fmachairo- 

 dont. The American species, f^". dakotensis, was the largest 

 carnivore of its time and not greatly inferior in size to the Lion. 



Still another White River fmachairodont, ]Dinictis, 

 differed in many interesting ways from its contemporary 

 fHoplophoneus, being more primitive and departing less from 

 the ordinary fissipede type of structure. This is shown by 

 the greater number of teeth, which was normally, i ^, c\, p |, 



