78 



THE WHITE RIVER BADLANDS 



CREODONTA 



The Cerodonts originated in the earliest Tertiary and 

 were evidently the predatory flesh eaters of their time. 

 They were the primitive ancestors of the true carnivores 

 and they held a position relative to contemporary animals 

 similar to that which the true carnivores hold among the 

 animals of today. 



Figure 22 — Skeleton of the Oligocene creodont Hyaenodon cruentus 

 Scott. 1895. 



There were numerous families but of all these only 

 the Hyaenodons, the latest and most specialized are found 

 in the White River badlands. (See Plate 25). The indi- 

 vidual fossils are not abundant although several species are 

 represented. The skull of the largest Hyaendon horridus in- 

 dicates an animal of wolf-like appearance approaching in 

 size the present day black bear. The life habits of these 

 animals are not entirely clear. It is not even known whether 

 they were digitigrade or plantigrade. They may have been 

 semi-plantigrade. It has been suggested that they were 

 semi-acquatic but this is quite uncertain. The Hyaenodons, 

 unlike most of the class, seem to have lived on carrion. 



CANIDAE 



The Canidae are abundantly represented in the White 

 River badlands. More than twenty species are known. The 

 earliest North American Canidae recognized as such are 

 found in the Upper Eocene. They first appeared in Europe 



