CHAPTER IV 



THE MIOCENE OF EUROPE, ASIA, AND NORTH AMERICA 



With the iDeginning of the Miocene we enter upon a new faunal phase 

 in Europe. We also enjoy our first knowledge of the life of Asia. The 

 hitherto pent-up mastodons of Africa enter Europe and later reach 

 North America; Asia toward the close of the Miocene sends great contri- 

 butions of its mammalian life into Europe and to a far less degree into 

 North America. In all probability at this time Africa receives certain 

 large contributions both from Europe and Asia, but of the exact period 

 when this Eurasiatic contribution to Africa occurred we have no direct 

 geologic record. The grand result of these intermigrations between the 

 great continents is that by the close of the Miocene, Africa, Europe, and 

 Asia probably constituted one zoological realm, arctoGjEA, with North 

 America as an outlyer, distant but yet related. 



This condition, which we shall speak of as the Fifth Faunal Phase, 

 continues until the Lower or Middle Pliocene, when South America unites 

 with North America and enters into this world-wide distribution of a 

 somewhat similar fauna, namely, of proboscideans, horses, tapirs, true 

 felids, and machaerodonts, canids, mustelids, and many families of rodents. 



V. FIFTH FAUNAL PHASE — MIOCENE TO LOWER PLIOCENE. 

 APPEARANCE IN EUROPE AND NORTH AMERICA OF AFRICAN 

 PROBOSCIDEA AND OF ASIATIC SHORT-LIMBED RHINOCEROSES. 

 CLOSE UNION OF THE MAMMAL FAUNA OF EUROPE, ASIA, AND 

 AFRICA. NORTH AMERICA MORE REMOTE. AND SOUTH AMERICA 

 STILL ENTIRELY INDEPENDENT. PROGRESSIVE EXTINCTION 

 OF BROWSING AND INCREASE OF GRAZING TYPES. A LOWERING 

 OF TEMPERATURE. INCREASING SUMMER DRY PERIODS AND 

 SEMI-ARID AREAS. 



Palceogeography and Climate 



Flora and climate of Europe. — There is evidence of a gradual lowering 

 of temperature. While the vegetation of the Miocene has much in com- 

 mon with the Oligocene and is characterized by an increase of species, 

 many forms now confined to warmer zones disappear from central and 



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