Moeritherium 

 (Eocene) 



Palaeomastodon 

 (Eocene- Oligocene) 



Fig. 20.7. Representative stages of evolution in the elephant familv, as shown bv the skulls of 

 selected genera. For proper comparisons of size, note that the lower two figures have been re- 

 duced twice as much as the upper three. The significant changes in the proportions of the 

 facial parts involve an initial lengthening of the chin, followed by a marked shortening. These 

 changes are correlated with the development of the proboscis, or trunk, and of the tusks. (Re- 

 drawn from R. S. Lull, 1908, American Journal of Science, Series 4, vol. 25, printed bv 

 permission.) 



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