276 



THE AGE OF MAMMALS 



pangolins (Manis), relatives of which, it will be recalled, first occur in the 

 Oligocene of Europe. 



The interpretation of this Lower Manchhar and Bugti fauna as a 

 whole is that it was collected from a forested region not inhabited by 

 grazing types, that it contains some survivals of European browsing types 

 of Oligocene and Lower Miocene age, and that it is chiefly of Middle and 

 partly of Upper Miocene age. 



III. MIOCENE LIFE OF NORTH AMERICA 



The greatest progress in recent years in American palaeontology is in 

 the revelation of the different phases of the Middle and Lower Miocene 



Fig. 137. — Chief Miocene and Lower Pliocene fossil mammal deposits of western North 

 America. 1. Typical Arikaree Formation, S. Dak., Nebr., Col. 2. Laramie Peak, Wyo. 

 3. Pawnee Creek Beds, Col. 4. Panhandle Beds, Tex. 5. Deep River Beds, Mont. 6. Mad- 

 ison Valley Beds, Mont. 7. Mascall Formation, Oreg. 8. Republican River, Kan., Nebr. 

 9. Santa Fe Marls, N. Mex. 10. Clarendon Beds, Tex. 11. Elephas imperator Beds, Tex. 

 (See text for horizons.) 



and their relation to the Oligocene. We owe this chiefly to the explora- 

 tions and studies of Scott, Matthew, Hatcher, and Peterson. 



No sudden geologic or life break occurs in America to separate Ohgo- 

 cene from Miocene times, such as that which so sharply demarcates these 



