XII. A MOUNTED SKKLKTON OK TITANOTHERIUM 

 DISPAR Marsh. 



By J. B. Hatchkr. 



The Titanotheres were by reason of their size and great nvniibers 

 among the more striking and characteristic of the larger mammalia 

 that inhabited the Northern Hemisphere in lower and middle Oligo- 

 cene times. The family had its origin in the early Eocene, the genus 

 Titanotherium being a direct descendant of Paleosyops from the 

 \\'ind River and Bridger formations through the genera Manteoceras 

 and Diplacodon of the Uinta. 



The family, although of considerable importance throughout the 

 Bridger and Uinta Periods, reached its culmination in the beginning of 

 the White River, and, singularly enough, died out at the close of the 

 period which witnessed the deposition of the sandstones and clays of 

 the Titanotherium beds, found at the base of the White River series. 



Their great size, as well as the pair of fronto-nasal horns with 

 which their skulls were i)rovided, afforded these beasts sufficient pro- 

 tection from the comparatively small contemporary predaceous ani- 

 mals. Moreover the character of their dentition was such as would 

 seem to have been admirably adapted for sustaining these animals on 

 a vegetable diet, more especially when the character of the vegetation 

 was of a growth sufficient to permit of its being received into the 

 front or sides of the mouth in considerable quantities, where by the 

 action of the large and powerful molars and premolars it would have 

 been easily detached and masticated. It is scarcely possible to con- 

 ceive of a more efficient mechanical device for the crushing and 

 grinding of vegetable food than were the molars of Titanotherium. 

 I'hus while the Titanotheres were well equipped with a most excellent 

 apparatus for masticating their food they were clearly deficient, 

 through the lack of functional, cupped superior or inferior incisors, in 

 the means requisite for procuring the necessary food supply from a 

 region clothed only with a rather sparse growth of vegetation, consist- 

 ing for the most part of short grasses, conditions similar to those which 

 prevail to-day throughout our Western plains. It is not at all im- 



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