150 



THE AGE OF MAMMALS 



true Hyoenodon of the Bartonian and Ludian. Northern Asia or Eocene 

 Europe appears to have been the home of the genus Hyoenodon, because 

 these animals do not appear in northern Africa and in North America 





.'^'^.i.V'' 



Fig. 52. — The New and Old World family of mesoiiychid creodonts, known in the Lower 

 Eocene of Europe and in the Lower to Upper Eocene of North America. Above : Skeleton 

 of the Middle Eocene (Bridger) Dromocyon vorax, in the Yale Museum. Below : Restoration 

 of a similar form. After original by Charles R. Knight, in the American Museum of Natural 

 History. 



until the Lower Oligocene. They are typically cursorial or running creo- 

 donts or primitive carnivores, capable of traveling great distances, and 

 thus finally enjoying a very wide geographic range, before extinction. 



