404 ORIGIN OF LIFE IN AMERICA 



of the marsupial Caenolestes and to its being the only living 

 member of the extinct family Epanorthidae. In the Santa 

 Cruz beds this and another family of herbivorous marsupials 

 are represented by several genera. Professor Sinclair * in- 

 clines to the belief that the South American Epanorthidae and 

 the Australian phalangers have had common ancestors. From 

 all these facts he concludes that a land connection between 

 Patagonia and the Australian region must have existed not 

 later than the close of the Cretaceous Period or the beginning 

 of the Tertiary Era, and that the interchange of marsupials 

 may have been effected between the two continents at this 

 time. 



Of all the similarities between the South American and 

 Australian extinct faunas none perhaps is more striking, re- 

 marks Dr. Smith Woodward,f than the essential identity of 

 the extinct Miolania in the two regions. He thinks there can 

 be no doubt that this creature was a truly terrestrial or marsh 

 chelonian. The theory of a former land connection between 

 South America and Australia seems, therefore, to receive 

 weighty support from the new discovery of this curious 

 reptile. 



It has also been urged that the Patagonian fossil fauna 

 indicates traces of an affinity with South Africa. Professor 

 Scott, J with some hesitation, expresses the opinion that the 

 resemblance of the solitary Patagonian insectivore Necrolestes 

 to the golden mole Chrysochloris of South Africa may be due 

 to genetic relationship. It is significant, in view of the early 

 Tertiary faunistic relationship of Patagonia and western 

 North America, to note that certain creatures resembling the 

 golden moles made their appearance in North America in 

 Oligocene and Lower Miocene times. I have had occasion to 

 allude to Xenotherium and Arctoryctes already (p. 246). The 

 affinities between these various forms are not very marked. At 

 any rate, it would be unsafe to draw any conclusions as to the 

 existence of a former direct land bridge between Patagonia 

 and South Africa from the presence of Necrolestes in the 

 Santa Cruz deposits. 



* Sinclair, W. J., " Marsupial Fauna of Santa Cruz," pp. 76 81. 

 t Woodward, A. Smith, "Extinct Eeptiles from Patagonia," p. 182. 

 J Scott, W. B., " Princeton Expedition," Vol. V., p. 379. 



