OSTEOLOGY OF CARNIVOROUS DINOSAURS. 



75 



by smooth but vertically concave ends. With the exception of the joint between 

 the first and. second phalanx of digit III, all of the other joints in the pes are keeled. 

 Those of the median or third digit are broad and illy defined, but the remaining artic- 

 ulations have a pronounced median keel on the proximal ends and a corresponding 

 median vertical depression on the distal 

 ends, thus forming strong joints that 

 would be difficult of lateral dislocation. 



Deep lateral pits are present on both 

 sides in all of the phalanges. The ter- 

 minal phalanges are moderately curved 

 bones, sharply pointed in front, deeply 

 grooved on the side for the external 

 claw, which in life would have con- 

 siderably increased the size of these 

 appendages. The unguals of digits II 

 and III are about subequal in size, while 

 those of digits I and IV are considerably 

 reduced. 



The ungual phalanges of the pes are 

 readily distinguished from those of the 

 manus, by the greater curvature of the 

 latter, and the inferior development of 

 the bone below the articulating surface 

 for the preceding phalanx, also those of 

 the manus are more compressed trans- 

 versely. The shape of these clawed 

 unguals, appear to indicate that these 

 feet were better adapted for locomotion 



x Fig. 52. — Left hind foot of Antrodemus valens Leidy. No. 



than lor grasping purposes. 473^ u.s.n.m. restored, j nat. size, (after marsh.) ' 



Measurements of left hind feet of Antrodemus valens Leidy. 

 DIGITS. 





No. 4734, U.S.N.M. 



No. 8123, U.S.N.M. 





1.1 



II. 



III. 



IV. 



I. 



II. 



III. 



IV. 



Greatest length'of metatarsals 



mm. 

 85 



mm. 



270 



60 



72 



42 



mm. 

 327 

 64 

 80 

 40 

 * 



mm. 



275 



90 



65 



36 



mm. 



mm. 

 320 



mm. 



353 



67 



80 



38 



mm. 

 324 



Greatest transverse diameter, proximal end . 







92 



Greatest transverse diameter^distal end 



Least transverse diameter of shaft 



38 





76 

 45 



57 

 36 









PHALANGIALS. 



Greatest length: 



Proximal row 



70 

 2 70 



120 

 80 



110 



2 90 



66 



75 

 50 

 30 

 29 





122 



116 

 94 



74 





Second row 



72 



Third row 









Fourth row 













FiftWrow '. 















2 75 



















First digit measurements are from the right foot. 



- Estimated. 



