524 THE TERTIARY PERIOD 



Isolation from North America and some sort of a connection with 

 Australia are clearly shown by these mammalian faunas. In the 

 Araucanian formation the northern forms at last make their 

 appearance. Wolves, Mastodons, Horses, Tapirs, Deer, Llamas, 

 have found their way to South America, just as southern Sloths 

 and Armadillos occur in the northern Pliocene. 



From the absence of means for direct comparison, there has 

 been much dispute concerning the true position of these South 

 American formations in the Tertiary system. The only point so 

 far at all well established is that the Araucanian beds cannot be 

 older than the Pliocene, for we have much independent geological 

 evidence to prove that the junction of North and South America 

 was made by the post-Miocene movement. 



