ANCESTRY OF ELEPHANTS. 



1 6. 



13 



Recent 

 Pleistocene 

 Upper Plioce fie 



ELEPHAS 

 (shortchin) 



Lower Pliocene TETRABELODON 



[LONGIROSTRIS STAGE 

 Uflfier Miocene (shortening chin) 



Middle Miocene TETRABELODON 



[ANGUSTIDENS STAGE] 

 Lower Niocene (longchin) 



UnnerOligocene 9* from Africa 

 into Lurone - 



Lower Olyocene PAL AEO MASTODON 



(lengthening chin) 

 ditto ditto \ 



n . [ MOERITHERIUM 



Upper Eocene y (short cflm) 



Lower Eocene 



Diagram showing- some stages in the gradual increase in size, and alteration 

 in form, of the skull and mandible occurring in the Proboscidea from 

 the Eocene to the present day. 



