MATTHEW, CLIMATE AND EVOLUTION 



259 



primitive ungulates would have taken, if they had reached the island; 

 but the case is not so clear. 



EDENTATA 



The edentate orders afford among the unguiculates a broad parallel in 

 their distribution and history to the Condylarthra and their successors 

 among the ungulates. Their extinction has been somewhat less complete ; 

 a few highly specialized survivors remain in the Neotropical, Ethiopian 



and Oriental regions. 



y/AXenart/n 



'^^^ Pholidota 



TuhuUdeii tata 



Fig. 29. — Distribution of the Edentate orders 



The New World edentates or Xenarthra may have originated in Cretaceous North 

 America, but their Tertiary dispersal centers were South American, apparently in or 

 near to Patagonia. The dispersal centers of the Pholidota and Tubulidentata would 

 appear to have been Palsearctic, but very little Is known of their fossil record. 



The super-order Edentata is an artificial assemblage including the 

 three surviving orders Xenarthra, Pholidota and Tubulidenta and the 

 extinct order Tseniodonta (= Ganodonta). The Tasniodonta of the Eo- 

 cene of North America may perhaps be regarded in a broad way as rep- 

 resenting the primary type of the Xenarthra, but even this is doubtful. 



