68 



BULLETIN 89, UNITED STATES NATIONAL MUSEUM. 



Measurements of coracoids. 



Greatest length 



Greatest height 



Greatest transverse width of glenoid fossa . 



Stegosaurus sp. 



No. 7362, 

 right. 



No. 7411, 

 right. 



FoKB Limb and Foot. 



The fore limb in Stegosaurus was very powerful, as is plainly evident from the 

 robust size of the bones and the great development of the processes of the humerus 

 and lower limb bones. The large size of the olecranon process imphes a bent limb 

 of the Ceratopsian type. There were five digits m the fore foot, which was of good 

 size and well adapted for supporting the great weight of this animal. 



Humerus. — The humerus is short and massive with widely expanded ends. 

 Below the center of the bone the shaft is greatly constricted and without meduUary 

 cavity. The roughened radial crest is well developed and extends from the supe- 

 rior extremity down the antero-extemal border tliroughout one-haK the length of 

 the bone. The rounded rugose head is situated somewhat internal to the center of 

 the proximal end (pi. 20, fig. 2^.) and is produced backward, overhanging the posterior 

 border of the shaft. The head passes on its inner side into an area roughened for 

 the attachment of muscles, which apparently is analogous to the lesser tuberosity 

 in mammalian humeri. The greater tuberosity is apparently represented by a 

 rugose, strongly developed ridge of bone runnmg down from the proximal end on 

 the postero-external border. 



The radial and ulnar condyles are weU differentiated and separated by a trochlea 

 depression of moderate width and breadth. 



The anconeal and trochlear depressions are about siibequal, the former perhaps 

 being the better defined. The supmator ridge (pi. 20, fig. 2s.) is a prominent feature, 

 and adds much to the transverse expansion of the distal end. In adult individ- 

 uals both proximal and distal articular ends are roughly rugose. 



In the National Museum there are eight humeri. The principal measurements 

 of a number of these will be found in the table below. In Stegosaurus stenops the 

 ratio in length of the humerus to the femur is 1 : 1 .9. 



Ileasureme^its of humeri. 





S. stenops. 



Stegosau- 

 TUS sp., 

 No. 7409. 



5. sulcatus, 



type No. 



4937. 



S. urujula- 



tun, No. 



6646. 



Type, No. 4934. 



No. 4929. 



Right. 



Left. 



Right. 



Left. 



Left. 



Eight. 



Left. 





mm. 

 572 

 304 

 265 

 101 



mm. 

 530 

 303 



mm. 

 506 

 315 

 237 



mm. 

 612 



452 

 276 

 202 

 102 



609 



610 

 347 

 283 

 114 



Greatest breadth proximal end 



227 

 103 



278 , 



lis 















