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 Reptiles from Patagonia,” p. 1S2. 
4 Sco.tt, W. 13., “ Princeton Expedition,” Yol. V., p. 379. 
