606 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



Manteoceras. — A graviportal, or short,- broad foot; 

 digits and metacarpals, however, not spreading 

 apart distally as in Palaeosyops. Brachypodal; de- 

 tailed proportions and facets of carpals resembling 



a bi'oad, flat face, subquadrate as seen from in front, 

 hook of magnum more symmetrical, broadly spatulate; 

 second phalanges abbreviate; terminal phalanges dis- 

 tinctly abbreviate, expanded distally, with a pro- 



D 



Figure 515. — Progressive graviportal adaptation in the pelvis of Eocene and Oligocene titanotheres 



A, Eotitanops borealis (subcursorial); B, Palaeosyops major (inediportal); C, Manteoceras sp. (subgraviportal); D, Brontotheriumlsp. (graviportal). 



One-eighth natural size. 



those of Mesatirhinus rather than those of the Palaeo- 

 syopinae; lunar high, resting chiefly on unciform with 

 a very oblique magnum facet; magnum relatively high 

 and narrow, with five facets in front view, acuminate 

 above, with lunar unciform facet continuous, forming 



nounced median groove. From the above description 

 it appears that Manteoceras resembles Mesatirhinus in 

 the proportion of the carpals. It differs widely in 

 the abbreviation of the metacarpals and especially of 

 the terminal phalanges. 



