FORMER LAND CONNECTIONS. 137" 



Schwarz found parts of the femur of a similar animal perhaps 

 nearly as large. 



Isolated at the close of the Cretaceous, even from Asia, a 

 fauna developed — so far known only from Egypt and the Victoria 

 Nyanza — peculiarly African, including primitive whales (Zeug- 

 lodon) and sea-cows (Sirenia), gigantic land tortoises, ostrich-like 

 birds, archaic Carnivora (Creodonta), and various primitive 

 Proboscidea such as the Mastodon and Dmotherium. Conspicuous 

 is the absence of the rhinoceroses, tapirs, and Equidae (horses), 

 which at that very time (Early Tertiary) were living in Europe. 



In the Miocene by the emergence of the Iranian-Himalayan 

 fold-ranges Northern Africa became linked to Asia, India, and 

 Europe, and an interchange of forms took place, though evidently 

 not upon an extensive scale, for even in the Pleistocene the fauna 

 in that part of Africa was still typically Ethiopian. Among the 

 contributions to Eurasia were the Proboscidea and ostriches, while 

 the immigrants were the rhinoceros, camel, lion, and other Felidae, 

 Equidae, bear, wild cattle, buffalo, and numerous antelopes. 



Together with the indigenous fauna these forms spread south, 

 so that we find the remains of the Mastodon in the Vaal River 

 gravels near Barkly West and extinct species of horse and buffalo 

 in vanous parts of the Cape and Orange Free State. 



This incursion of northern fcrms was doubtless assisted by the 

 cold of the approaching Pleistocene Ice Age, which pressed them 

 into the Oriental and Indo-Malay region also. It is known that, 

 during this particular period, glaciers descended the flanks of Mts. 

 Kenia and Kilimanjaro, and what more likely than that the spread- 

 of the temperate floras along or across the equatorial belt was 

 facilitated, if not wholly brought about, by the prevailing lower 

 temperature of the time. 



It was during the Tertiary that the crust subsided along 

 narrow belts forming the well-known "Rift Valleys" of Africa, 

 and the fracturing was attended by extensive volcanic eruptions; 

 some of the volcanos are still active. The northern end of the 

 belt of subsidence enters the Red Sea, while a strip of tilted and 

 fractured Miocene marine strata inland from Beira indicates the 

 southern extension of this lengthy arc along which the sides have 

 been drawn apart, allowing a narrow width of strata to drop 

 between them. 



The Reunion of Madagascar and Africa. 



Under such circumstances the temporary reunion of Mada- 

 gascar to the mainland in about the Miocene would have been not 

 only possible, but very probable, receiving some support from the 

 fact that this large island shows the effects of tilting and of frac- 

 turing, and is still subject to earthquake shocks, while it and the 

 other members of the Mascarene Group are surrounded by barrier 

 reefs of coral pointing to recent subsidence. Several of the 

 islands, Mauritius for example, are of recent volcanic origin and 

 possess differing faunas. 



