134 THE WANDERINGS OF ANIMALS [OH. 



Rhinoceros. 



The whole drama of the evolution of the true 

 rhinos has been played in Eurasia. 



In the Oligocene of Europe and America appear 

 hornless Aceratheres and pair-horned Diceratheres, 

 e.g. also Arsinoetherium of Egypt. None of the 

 right-and-left horned beasts have left descendants; 

 nor did the hornless forms in America, but in Asia 

 some introduced the principle of median horns and 

 such single and tandem-horned rhinos alone have 

 survived in the Old World, whilst those which reached 

 America in mid-Miocene times died out. 



Two-horned Old World species are : R. suma- 

 trensis ; R. etrmciis, in Pliocene and early Pleistocene 

 Europe ; its much larger and very hairy successor 

 R. megalorhinus of mid-Pleistocene Europe ; R. ticho- 

 rhinus-antiquitatis, of the steppes and tundras of 

 interglacial Europe and Siberia, closely related to the 

 black or long-lipped and the white orsquare lipped 

 rhinos of Africa. R. indicus has one horn. 



Tapirs. 



The cradle of the future tapirs stood somewhere 

 in Northern Asia ; the earliest recognisable genus 

 Systemodon of the American Lower Eocene being 

 a blind offshoot. With the Lower Oligocene appears 

 Protapirm in Europe ; it found its way into North 



