OSTEOLOGY OF CARNIVOROUS DINOSAURS. 



57 



Cor 



Williston * in 1901 in describing some limb material secured by him in Wyo- 

 ming, refers to the so-called Allosaurus fore limb figured by Marsh in the following: 

 There were two scapulae obtained that certainly show a generic distinction from Allosaurus, as I 

 have convinced myself from inspection of the scapula referred by Marsh to that genus, and figured by 

 him in various places. It remains to be seen, 

 however, whether this scapula of Marsh indu- 

 bitably belongs with the bones first referred by 

 him to Allosaurus. I do not think there is 

 conclusive evidence of this. 



The facts regarding this scapula as 

 presented on a preceding page bears 

 out Doctor Williston's contention. 



The limb described and figured by 

 Williston undoubtedly belongs to the 

 genus Antrodemus. Its close resem- 

 blance may be clearly seen by com- 

 paring his illustration with figure 40. 



Scapula (Sc.) — Both scapulae are 

 preserved with the present specimen, 

 the right being perfect, as shown in 

 plate 5, figure 2, with the exception 

 of a small portion of the upper ante- 

 rior corner of the blade, which is 

 missing. The left scapula was in- 

 jured in life, and subsequent healing 

 produced the deformation shown in 

 plate 5, figure 1. This pathologic 

 condition caused a widening of the 

 blade that would be entirely mislead- 

 ing as to its true form had not the 

 opposite scapula been present. The 

 scapula of Antrodemus is distinctive 

 on account of its bird like form as has 

 previously been pointed out by Wil- 

 liston. 2 The shaft is exceptionally 

 long and slender, being nearly of equal 

 width throughout, except the upper- 

 most or distal extremity which is per- 

 ceptibly widened. This expansion 

 is about equal in fore and aft direc- 

 tion. The upper third is flattened 

 and thin, while more proximally the 

 shaft is trihedral in cross section, the 

 anterior border being sharp, the posterior one rounded. Longitudinally the exter- 

 nal surface is convex, though nearly straight in its middle portion, a shape that 

 probably conformed closely with the convex curve of the body cavity. The inner 



Fig. 40.— Right fore limb and foot of Antrodemus valens 

 Leidy. Cat. No. 4734, U.S.N.M. J nat. size. Lateral view. 

 C 2 carp ale two; Cot, coracoid; h, humerus; in, intermedium; 

 t, radius; ro, radiale; Sc, scapula; u, ulna; I, II, and III, 



DIGITS ONE, TWO, AND THREE. THE POSITION OF THE MISSING 

 ULNARE IS INDICATED BY DOTTED LINES. 



i Amer. Journ. Sci., vol. 11, 1901. p. 112. 



2 Idem, p. 113. 



