4' BULLETIN 15 3, UNITED STATES NATIONAL MUSEUM 



be surviving pieces of this former forest, and the vast expanse of 

 steppe and savannah country that now occupies so much of eastern 

 Africa, to say nothing of the true deserts in the Kalahari and 

 Sahara, are considered as much more recent in origin than the low- 

 land forests. In other words, vast stretches of wooded land became 

 drier and the trees gave way to the more arid vegetation of the 

 savannahs. With this tremendous ecological change in the flora came 

 an equally marked change in the fauna. As Lonnberg (pp. 13, 14) 

 remarks — 



* * * a certain number of forest animals were able to survive and more 

 or less accommodate themselves to a life on the steppe, since the forests had 

 been destroyed. The steppe fauna would, however, have been very poor in- 

 deed, if an invasion from abroad had not taken place. Recent discoveries 

 have also revealed that such an invasion began already in Pliocene. * * * 

 Thus quite a new fauna including many members typically adapted to lead a 

 life on a steppe had made its appearance on the African soil. 



The question then arises from where did it come? Certainly from the north- 

 east and north, because thrnngh upheaval Africa now had become broadly con- 

 nected with Asia and secondarily also with Europe. At Pikermi in Greece, 

 on Samos and in the Siwalik Hills in Northern India and other places have 

 been found great quantities of fossils, * * * among them many mammals, 

 which stand in close relationship to the African steppe fauna, as giraffes, 

 antelopes, horses, etc. The new African fauna has thus witliout doubt come 

 about this way. 



In other words, the fauna that flourished in the steppes of central 

 and south-central Asia during the Pliocene is very similar to the 

 present-day life of the east African plains. When the connection be- 

 tween Africa and Asia by means of Asia Minor and Arabia was es- 

 tablished, a fully developed savannah and steppe fauna was ready to 

 spread over the open country of Africa at once. The exodus from 

 the Asiatic steppes to the African grasslands was probably a very 

 rapid one and one of a magnitude without a jDarallel in other regions 

 of the world. > 



Thus arrived the ancestors of all those mammals, that we regard as typi- 

 cal for the African steppe, as antelopes, buffaloes, giraffes, zebras, rhinocer- 

 oses (of modern type), * * * hyenas and a lot of other carnivorous 

 mammals. 



This new fauna consisted, however, not only of mammals but also of birds 

 and reptiles etc., whicli, although they now * * * are regarded as typical 

 Africans, in reality originated from Asia. 



Thus, we have fossil evidence of ostriches in Mongolia {Struthio- 

 lithus) and a living form in the Arabian-Syrian desert, linking up 

 with the well-known ostriches of the African plains. There could 

 have been no ostriches in Africa before the forest gave way to the 

 grasslands, and the Mongolian fossil form is of the same age as the 

 transcontinental African forest. Therefore, it is clear that the os- 



