296 



THE AGE OP MAMMALS 



of Europe, but actually related to the caviconi antelopine or bovid division, 

 of the Ruminantia. Species of Dromomeryx from Colorado {D. horealis) 

 belong to an animal of the size of the existing Virginia deer. The horn 

 pedicles are without 'burr,' apparently not deciduous and probably en- 

 closed in a horny sheath as in the true antelopes and cattle. 



There is a great variety of canids both of the long- and short-faced types. 

 The abundance of these animals in the Miocene of North America, contrasted 



Fig. 



148. —The rpiM'i- Midccnc forest-li\-inir (ir hrow.sing horse Ili/im/ii /)it:is. .Vfter original 

 by Charles R. Knight in the American Museum of Natural History. 



with their subordinate position in Europe, renders it very probable that 

 this continent was the chief center of their adaptive radiation. As studied 

 by Scott, Matthew, and Merriam, they are in a high degree polyphyletic, 

 including five or six distinct lines, as follows : The typical dogs, descendants 

 of Cynodictis of the Oligocene, are represented by Tephrocyon and lead in 

 the direction of Canis. The cyons or dhole-like dogs are successors to the 

 Temnocyon and Daphwniis of the Oligocene with trenchant-heeled grinding 

 teeth, and are represented by Cyan and Icticyon. The giant or bear-like 

 dogs are represented by Amphicyon. The mustelid family is represented 

 by a species of marten, by a primitive otter, as above noted, while the 

 felids of Colorado are represented only by specimens doubtfully referred to 

 the European Pseudcelurus. It is noteworthy that none of the machae- 

 rodonts have been discovered at this stage, although they are abundant both 

 in older and in more recent formations. 



