EVOLUTION OF THE SKELETON OF EOCENE AND OLIGOCENE TITANOTHERES 



687 



Longitudinal axial measurements of vertebrae 



MillimelDrs 



7 cervicals, as mounted, anteroposterior 600 



17 dorsals, as mounted, anteroposterior 1, 270 



3 lumbars, anteroposterior 230 



Sacrals (crushed) , anteroposterior 150 



21 caudals, anteroposterior 1,000 



Atlas, ventral arch, anteroposterior 65 



Axis, length (ventral, omitting the odontoid tip) 110 



Sixth cervical, ventral length of centrum S6 



First dorsal, height of spine 43 



Rihs. — The ribs are long and slender, and the chest 

 was probably narrow. The sixth rib is the longest. 

 The estimated length of some of the ribs on the right 

 side is as follows: 



Millimeters 



R 1. 

 112. 

 R5- 



Millimeters 



445 



530 



795 



R6.- 



R8_- 

 R 17- 



870 



515 



Fore limh. — As mounted the height from the top of 

 the scapula to the ground is 2,400 millimeters, the 

 lengths of the successive segments being, scapula 640, 

 humerus 557, radius 525, manus 350. Tlie scapula is 

 very distinctive in type, being long and narrow ante- 

 roposteriorly. The glenoid is narrow, and so is the 

 coracoid process. The spine is but little expanded, 

 and the postscapular fossa is not greatly extended 

 posteriorly. The humerus, altliough considerably 

 crushed, is profoundly different in proportional char- 

 acters from that of Brontops rohustus, being long and 

 slender, with a small crest on the great tuberosity and 

 less developed deltoid and supinator crests. The 

 radius and ulna also are long and slender; the ole- 

 cranon is very deep, laterally compressed, and with a 

 deep terminal groove. The manus is high and narrow 

 with long metacarpals and a narrow carpus. The 

 scaphoid is narrow, with a deep concave facet for the 

 trapezoid, which was vertically high. The lunar is 

 narrow, with a fair-sized facet for the magnum. 

 The magnum also is rather narrow. The unciform is 

 deeply extended downward on the outer side, for 

 Mtc V. The terminal phalanges are narrow. 



Measurements of fore limb 



Millimeters 



Scapula, height (middle of glenoid to dorsal border) 640 



Scapula, width (at right angles to preceding measure- 

 ment) 460 



Humerus, length (head to capiteUum) 557 



Humerus, right, extreme length 620 



Radius, right, midlength 525 



Radius, width of head 145 



Radius, width of distal end 125 



Ulna, length 660 



Manus, length 350 



Width across distal end of radius and ulna 170 



Carpus, width 149 



Carpus, height, lunar to summit of Mtc IV 80 



Scaphoid, width 52 



Scaphoid, height 47 



Lunar, width 65 



Lunar, height 72 



Trapezoid, anteroposterior 47 



Mtc II, height 214 



101959— 29— VOL 1 17 



Millimeters 



Mtc III, height 233 



Mtc IV, height 225 



Mtc V, height (estimated) ^ 191 



Terminal phalanx of D. II, right, width 34 



Terminal phalanx of D. Ill, right, width 43 



Terminal phalanx of D. IV, right, width 38 



Terminal phalanx of D. V, right, width 29 



Pelvis and Jiind limb. — The hind limb also is long 

 and slender, the total height of the hind limb as 

 mounted being 1,430 millimeters; the height from the 

 top of the ilium to the ground 1,900. The pelvis is 

 elongate and narrow (partly increased by pressure), 

 the total length being 820 millimeters, and the 

 breadth as mounted 830. The length of the outer 



Figure 619. — Manus referred to Menodus 

 giganteus 



Yale Mus. 12012. Figure prepared by Berger under direc- 

 tion of Marsh. Ob^er^e the small terminal phalanges 

 and the relatively high, narrow lunar. Slightly less 



' than one-flfth natural size. 



part of the crest of the ilium is 580, of the inner part 

 290. The femur is extraordinarily long and slender. 

 The hind feet are poorly preserved and do not give 

 much character. 



Measurements of hind limb 



Millimeters 



Femur, midlength 703 



Femur, least width of shaft S5 



Tibia, length 430 



Astragalus to Mts III 302 



Menodus giganteus 



The postcranial skeleton of this species is positively 

 known chiefly from a scapula and a series of vertebrae 

 in the Field Museum (No. 5927), which is associated 

 with a superbly preserved skull. (See p. 535.) An 

 astragalus associated with the fine skull Am. Mus. 



