PRAIRIE 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 a 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, C. IL, “Revision of the Coyotes.” 
t Matthew, W. D., “ Carnivora and Insectivora of the Bridger,” pp. 32S 
—350. 
