CERATOPSIAN DINOSAURS FROM MONTANA — GILMORE 



11 



on the sides for the attachment of ligaments on most of the phalanges. 

 The ungual phalanges are depressed as in all predentate Dinosauria, 

 rather bluntly pointed, and slightly curved longitudinally. Digit III 

 bears the most robust ungual. 



There is a striking resemblance between this pes and that of 

 CmnptosauTus, in its general structure. The compact, strong articu- 

 lations of the metatarsals and phalanges show Leptoceratojys to have 

 one of the most specialized hind feet of any known quadrupedal 

 dinosaur with the exception of Protoceratops, which it closely 

 resembles. 



Table 2. — Measurements of hind foot of Leptoceratops sp. {U. S. N'. M. No. 13863) 



Measurement 



Digits 



II III IV 



Greatest 

 Greatest 

 Greatest 

 Greatest 

 Greatest 

 Greatest 

 Greatest 

 Greatest 

 Greatest 



length of metatarsals 



anteroposterior diameter, proximal end- 



transverse diameter, proximal end 



transverse diameter, distal end 



length of first row of phalanges 



length of second row of phalanges 



length of third row of phalanges 



length of fourth row of phalanges 



length of fifth row of phalanges 



Mm. 



15. 3 

 41.4 



Mm. 

 100 

 16. 5 

 17.5 

 18 

 38 

 31 

 35- 



Mm. 

 108 



23 



37 



27.5 



29.5 



41 



Mm. 

 92 

 15. 5 

 19 



17 



21 

 21 



18.5 

 31- 



Pelvic hones. — Portions of both ilia preserved with specimens 

 U.S.N.M. No. 13864 resemble those of Protoceratops in having the 

 blade portion nearly vertical and without the reflected upper border, 

 found in other members of the Ceratopsidae. These bones bear a 

 much closer resemblance to the ornithishian ilium than to those of 

 the true horned dinosaurs. Shaft portions of both ischia of this 

 same specimen (fig. 9) show them to be somewhat curved, as con- 

 trasted with the straighter ischia of Protoceratops. 



Both Brown {loc. cit.) and Lull ^ have already stressed many points 

 of resemblance between Leptoceratops and Protoceratops, and these 

 newly acquired materials still further emphasize the nearness of this 

 relationship. The genera, however, are distinctly separate, and I am 

 in full accord with Lull who points out their wide divergence from all 

 other members of the Ceratopsidae. 



' Mem. Peabody Mus. Nat. Hist., vol. 3, pt. 3, 1933. 



