PEAIRIB DOGS 149 



Cynomys, however, is certainly of American origin, though 

 some of its near relations, as I have shown, have probably an 

 Asiatic ancestry. 



The coyotes or prairie wolves have been described as the 

 most inveterate enemies of the prairie dog. They are small, 

 graceful creatures hunting in packs like other wolves, but 

 living in burrows on the plains. Not long ago only a single 

 kind of coyote (Canis latrans) was recognised. More than a 

 dozen species are distinguished now ; some of them on rather 

 slender grounds.* All these occur west of the Mississippi. 

 The presence of wolves in the Arctic regions of America has 

 been alluded to (p. 11 and p. 61), but I have not hitherto 

 made any remarks on their past history and origin. 



The dog tribe (Canidae), to which all wolves belong, is 

 more widely spread in the world, that is to say, it has a larger 

 geographical distribution than any, other family of carnivores, 

 one species being even found wild in Australia. Judging 

 merely from the extent of its range, the family Canidae should 

 be a very ancient one, and this assumption is fully borne out 

 by the knowledge we have obtained from fossil remains of the 

 dog tribe. 



According to one of the most recent views, it would seem 

 as if the Cretaceous ancestors of the Carnivora, the great 

 order to which the do^ tribe belongs, were a group of small 

 arboreal mammals resembling the opossum in size and 

 habits, while more nearly allied to the primitive Insectivora. 

 The most strictly terrestrial types, such as the Canidae and 

 Hyaenidae, have departed widely from the primitive skeletal 

 structure. In the Eocene we already find several families 

 of the Carnivora fully developed, one of which, the Miacidae, 

 is regarded by Dr. Matthew f as the precursor of the dog 

 family. 



The latter originated in Oligocene times, but it was not until 

 the Miocene , Period that the genus Canis marked its first 

 appearance in America and Europe simultaneously. Since 

 it is highly improbable that the same genus should have arisen 



* Merriam, 0. H., "Eevision of the Coyotes." 



t Matthew, W. D., " Carnivora and Insectivora of the Bridger," pp. 328 

 —350. 



