654 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



zygapophyses almost horizontal. The single lumbar 

 centrum preserved is considerably longer than the 

 above-described dorsal vertebrae and exhibits a stout 

 keel; spine broad and grooved posteriorly; zygapoph- 

 yses rounded and vertically placed. 



midsection the spine much expanded along the border 

 and overhanging the postscapular fossa. The parts 

 preserved indicate that the scapula was lofty, with a 

 rounded suprascapular border unlike the somewhat 

 angular border of the Oligocene Menodus scapula. 



Figure 594. — Vertebrae and fore limb of Diplacodon or Prolitanoiherium 



Princeton Mus. 10390; Uinta C. After Scott and Osborn. Ai, A2, Front and side views of a cervical vertebra; B, a dorsal 

 vertebra (D. 7-10?), side view; Ci, Cj, side and rear views of a lumbar vertebra; D, incomplete left scapula; E, rear view 

 of left humerus; Fi, left humerus, radius, and ulna, outer side view; F, left radius and ulna with manus, front view, 

 oblique perspective. One-sixth natural size. 



The scapula of the same individual (Princeton 

 Mus. 10396) is preserved, its total length being esti- 

 mated at 600 millimeters (fig. 594). The characters 

 are as follows: Coracoid process a stout tuberosity; 

 glenoid fossa elongate, a rather shallow oval; spine 

 ascending gradually from the neck and passing without 

 an acromion process into a deep, recurved ridge; in 



The humerus (fig. 594) of the same specimen (Princeton 

 Mus. 10396) lacks the head, lesser tuberosity, and 

 bicipital groove. Its chief characters are as follows: 

 Stout deltoid ridge, terminating in a prominent 

 recurved hook; the inner length is estimated at 450 

 millimeters; shaft twisted upon itself, as in Rhinoceros; 

 supinator ridge less distinctly marked and less promi- 



