THE MIOCENE OF EUROPE, ASIA, AND NORTH AMERICA 249 



horsps, which rapidly evolve, as well as of the plains-living hares. Other 

 contrasts will be brought out in detail as we follow the history of Europe 

 and America independently. 



The foregoing tables and contrasts show rather a unity of ancestral 

 stocks than a genuine faunal reunion in the Lower and Middle Miocene 

 of the New and Old Worlds, because the invasion of North America by 

 the nomadic mastodons and teleocerine rhinoceroses cannot be cited as 

 evidence of a widespread interchange of life. Thus we cannot draw close 

 parallels between the Miocene divisions of the New and Old Worlds. They 

 may be broadly divided as follows: 



I. MIOCENE LIFE OF EUROPE 



As indicated in our earlier discussion of this wonderful fauna (p. 246), 

 the Miocene life of Europe may be divided into two grand phases, as follows : 



The Newer Fauna of the Upper 

 ^Miocene. 



The Older Fauna of the Lower and 

 Middle Miocene. 



Second or Asiatic invasion, introduction of 

 numerous plains-living, grazing, hypso- 

 dont types. 



First or African invasion. Continuation 

 and partial extinction of the Oligoccne 

 mammals. Continued prevalence of 

 browsing, brachyodont, and river-border 

 types. 



The Older Fauna 



Prevalence of browsing types. — In the older fauna we observe the dying 

 out of all the large Oligocene mammals except the chalicotheres. Of the 

 large mammals the imposing element is found in the newly arriving mas- 

 todons and dinotheres, which gradually evolve throughout the Oligocene. 

 Attention should be called to the fact that these huge animals, as well as 

 the flat-horned antelopes (Protragocerus), the tapirs, the anchitheres, the 

 teleocerine rhinoceroses, the chalicotheres among the Herbivora, are all 

 rather clumsy or slow-moving forms. The prevailing Carnivora (Am- 

 phicyons and Dmocyons), highly characteristic of the period, are also clumsy 

 and slow-moving. The relatively small and light-liml)ed tragulids {Dor- 

 catherium) and cervulines (Dicrocerus) are related to the forest- and swamp- 



