466 THE AGE OF MAMMALS 



Characteristic mammals. — In the various grand deposits of the forested 

 regions of the East and far West in which the mammaUan hfe is recorded, 

 successive phases of this great period of time, which will undoubtedly be 

 divided into sub-zones, arc indicated in the very gradual extinction of the 

 older forms and the appearance of newer forms, including modern species. 

 In a broad way this fauna seems to correspond with the second faunal zone 

 of Europe, i.e. it contains the animal life of a temperate climate; in other 

 words, it does not embrace any mammals of the northern tundras or steppes ; 

 neither the typical musk ox (Ovibos), the reindeer (Rangifer), nor the true 

 northern mammoth (E. primigenius) are within it. 



In addition to what is noted above, the prevailing mammals of this 

 fauna appear to be as follows : 



Columbian mammoth {E. columbi), in the west and southeast. 

 Mastodon (M. americanus), very abundant in the east, rare in the 



west. 

 Horses, fairly abundant in all parts of the United States. 

 Tapirs, fairly abundant in the forested regions of the east and 



southeast, not recorded in the west. 

 Llamas, no longer found in the east and southeast, but surviving 



in the west, perhaps in Oregon, and certainly in California until 



near the close of this life zone. 

 Mylodon, sometimes associated in earlier deposits with Megalonyx, 



disappearing in the more recent deposits. 

 Megalonyx, surviving throughout, abundant in the east and on the 



Pacific slope. 

 Megatherium, recorded in association with this fauna at Skidaway 



Island in Georgia and in South Carolina. 

 Bison (B. latifrons, B. antiquus), widely distributed in the east and 



west. 

 Moose (Alces), appearing in the west, doubtfully recorded in the east. 

 Virginia deer (Odocoileus) , abundant. 

 The peccary (Mylohyus) replaces Platygonus, or represents it in the 



forest fauna. 

 Relatives of the great musk sheep, or musk ox (Euceratherium, 



Preptoceras) , appearing in late deposits in the west. 

 Mountain goat (Oreamnos) of the rupicaprine family, appearing in 



late deposits in the west. 

 The marmot (Marmota), appearing in late deposits in the west. 

 Tree porcupines (Erethizon), widely distributed throughout the 



United States. 

 Castoroldes, a giant beaver-like rodent, widely distributed in the 



eastern and middle states, but apparently not extending to the 



south. 



