256 GEOLOGY. 



River) so far as known, and may be regarded as foreshadowing the 

 deer (Cervid(v). Being a highly specialized form, it had a short career, 

 as specialized forms usually do. 



In a similar way the ruminants seem to have been introduced or 

 foreshadowed by the Tragulidcc, the chevrotains, which are now repre- 

 sented in Farther Asia by a slender little ruminant, isolated and 

 scarcely known, the Tragulus, "the scarcely altered survivor of a 

 great tribe which flourished abundantly in Europe, and less so in North 



Fig. 441. — Skull of a Protoceras-YAze animal (Syndyoccras cooki Barbour), recently 

 discovered in the Loup Fork beds of Nebraska. (Photo, by Barbour.) 



America, before the typical and fully differentiated ruminants had made 

 their appear ance." 1 



The oreodons were small animals, never exceeding the size of a 

 large dog, and are interesting chiefly as a primitive form that lived on 

 from the Eocene with little change, while its contemporaries were either 

 rising to climaxes and disappearing, or were evolving into modern and 

 more lasting forms. They seem to have been exclusively North Ameri- 

 can, and lived on till the late Miocene. 



1 A. Smith Woodward, Vert. Pal., p. 360. 



