Article XIII.— FORE AND HIND LIMBS OF SAUROP- 

 ODA FROM THE BONE CABIN QUARRY. 



Dinosaur Contribution No. 6. 



By Henry F. Osborn and Walter Granger. 



During the early months of 1900 the large collection of limb 

 bones from the Bone Cabin Quarry was measured and compared 

 by Mr. Granger in preparation for this paper. Measurements 

 are chiefly of value in detevnuning J>r(?/>£>r^w//s j size, of course, 

 constantly increasing with age. Further studies during the present 

 year enable us to establish the following points : 



1. The proportions and relations of the radius and ulna in 

 the Sauropoda are remotely analogous or 'parallel with those of 

 the Proboscidia, owing to the marked extension of the ulna, the 

 similar weight, and the perfected quadrupedal progression in the 

 two types. 



2. The chief characters of the fore and hind limbs and of the 

 upper part of the manus of Diplodocus. 



The conclusion reached provisionally by Osborn,' that Diplo- 

 docus was a distinctively long-limbed type, is abundantly con- 

 firmed. The bones of the fore and hind limbs of Diplodocus can, 

 in fact, be readily identified by their relative length and slen- 

 derness as compared with those of Morosaurus and Brontosaurus 

 (see Fig. 6). 



3. The carpus in the Sauropoda includes the probable coosifi- 

 cation of the radiale and intermedium into a " scapho-lunar " ; 

 also a large ulnare, and from two to three small osseous carpalia 

 in the distal row. 



In his numerous and valuable contributions to this group the 

 late Professor Marsh left the homologies of the carpals undeter- 

 mined ; his figures (of the Morosaurus and Brontosaurus fore limb) 

 do not indicate the anterior crossing of the radius and ulna ; he 

 also left the limb structure of Diplodocus practically unknown. 



In general, the limbs of the three contemporary Sauropoda of 

 the Como district can be distinguished as follows : 



' Fore and Hind Limbs of Carnivorous and Herbivorous Dinosaurs from the Jurassic of 

 Wyoming. Bull. Amer. Mus. Nat. Hist., Vol. XII, 1899, pp. 161-172. 



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