OLIGOCENE OF EUROPE, NORTH AFRICA, AND NORTH AMERICA 203 



Fig. 92. — Rostoratiou of the head of the prim- 

 itive proboscidean Moeritherium of the Upper 

 Eocene of the Faydm, Egypt. (The eyes are rela- 

 tively too conspicuous.) After original, modeled 

 under the author's direction, by Erwin S. Christman 

 in the American Museum of Natural History. 



coneys of the Sinaitic Peninsula and of Africa. The living hyraces are 

 relatively of diminutive size. It would appear from the varied nature 

 and abundance of these ani- 

 mals that Africa was the chief 

 center of their adaptive radia- 

 tion. 



Still more important are 

 the two primitive members of 

 the order Proboscidea, Moeri- 

 therium and PalaomaModon. 

 The former is a sub-aquatic 

 mammal which presents its 

 chief resemblances to the Pro- 

 boscidea in the enlargement of 

 the same pair of front teeth as 

 those which constitute the tusks 

 of elephants; also in the struc- 

 ture of the grinding teeth, 

 which are essentially ancestral 

 to those of Palceomastodon. 



Other parts of the animal exhibit analogies to fhe primitive sea-cows or 

 sirenians. 



The other type, PalcEomastodon, appears to be directly ancestral to the 

 Lower Miocene mastodons of Europe; in contrast with Moeritherium, it 

 probably possessed a long prehensile upper lip, a pair of spoon-shaped 



lower incisor teeth 

 which opposed this lip, 

 a pair of upper incisor 

 tusks well developed 

 as fighting weapons, 

 with an enamel band 

 on the outer sides. 

 The grinding teeth are 

 more complex than 

 those of Moeritherium 

 and directly ancestral 

 in form to those of 

 Trilophodon angusti- 

 dens of the Lower 

 Miocene of Europe. 

 T- no T. ^ ^- r ^1 1, J r ..1, ■ :■ The accompanying 



b IG. 93. — Restoration of the head of the primitive pro- i ^ <=> 



boscidean Palceomastodon of the Lower Oligocene of the FayOm, models of the hcads 



Egypt. After original, modeled under the author's direction, fPio's Q*^ QS") exhibit 



by Erwin S. Christman in the American Museum of Natural V & • -^> 



History. the profound differ- 



