HASEMAN, GEOGRAPHICAL D I ST RIB UTION IN 80 UTH A ME RICA 87 



isted during the lower Permian in Brazil, they may also have been only 

 local glaciers of high altitude, like those existing in the Andes. 



Keturning again to the fact that the Gangamopteris flora only existed 

 during the formation of the Piano Alto, it appears to me that this is 

 positive evidence that its environment, composition and extinction were 

 directly associated with this great transformation of the South American 

 topography. In other words, the Gondwana flora was an arid highland 

 flora. 



It is known in marine series in Australia, but it could have been washed 

 there from higher elevations, and the altitude of these sandy highlands 

 was not necessarily great, in view of the fact that stunted plants are 

 found on the Brazilian highlands at comparatively low altitudes. Similar 

 geological transformations also occurred in India, Africa and Australia. 

 Similar deposits of shales, clays, sandstones, coal, etc... occur in these 

 remote regions. The mere fact that all of these regions possessed almost 

 identical environmental complexes, not known to be perfectly duplicated 

 in the northern hemisphere, is one of the most important factors con- 

 nected with the origin, the distribution and extinction of the Gangamop- 

 teris flora, regardless of whether these regions were or were not con- 

 tinuous. 



It is a remarkable fact that so many identical species and genera 

 belonging to different families of both the Gangamopteris and the cosmo- 

 politan flora could exist, unchanged, in such remote regions as India 

 and Brazil during most of the Permian epoch. Little short of ortho- 

 genesis or similar evolution in similar environments can account for such 

 data. 



I have already shown that the Permian inland basin of South America 

 is almost completely surrounded by higher Archean mountains which 

 have apparently remained almost stationary during part of and since the 

 Permian epoch. This is particularly true of southern Brazil. There- 

 fore, the fact that the Gondwana flora, so widely distributed over the 

 southern hemisphere, was able to enter these various Permian formations 

 over and around higher Archean mountains is evidence that its ancestors 

 were little or not at all affected by barriers. It is true that this flora 

 might have entered the outlets of the basin along the Permian coasts, 

 but if it was a highland flora, it probably did not. 



I am unable to conceive how and from where enough of the typical 

 deposits of Gondwana Land could be derived in such a way that a 

 homogeneous environment might have existed between either Africa and 

 South America, or between South America by way of the Antarctic 

 islands and either Africa or Australia. The Gondwana formation of 



