NO. 2241. NEWLY MOUNTED STEGOSAURUS STENOPS—OILMORE. 385 



Wyoming. None of the bones used in the mount were found more 

 than 90 feet distant in the quarry from No. 6531, which forms the 

 basis of the mount. It is quite possible that some of these bones 

 may have originally belonged to that skeleton. A considerable num- 

 ber of elements for which bones of the proper size and proportions 

 were not available have been restored. As is customary the restored 

 portions were given a color sufficiently distinctive to make them easily 

 recognized from the originals. 



The skeleton as mounted measures 14 feet 9 inches in length be- 

 tween perpendicular uprights and 7 feet 11 inches high from the 

 base to the top of the dermal plate above the hips. The Yale speci- 

 men is much larger, being 19 feet 5 inches long, and 11 feet 10^ inches 

 from the base to the top of the highest plate. The much smaller size 

 of the specimen in the United States National Museum may be 

 attributed not only to its pertaining to a smaller species but also to 

 the fact that the bones composing it were of individuals which had 

 not reached their maximum development. 



The actual articulation of the skeleton brings out some features 

 in the proportions of the animal that would hardly be appreciated 

 in a study of the individual bones. The wide hips (see pi. 60), 

 necessitating a corresponding expansion of the posterior thoracic 

 ribs, the flat-sided anterior half of the body (see pi, 59), the rapidly 

 drooping tail, the pose being clearly indicated by the wedge-shaped 

 centra of the anterior caudals. In the latter respect this mount is 

 in striking contrast to the Yale specimen, which has the tail high 

 above the ground. It was particularly gratifying to find that when 

 the dermal plates were properly spaced above the backbone that 

 the number required was in close agreement to an earlier expressed 

 opinion ^ " that there are not more than 18 in the complete series of 

 flat plates." In this specimen 19 were required to complete the two 

 rows, and it would now appear that, allowing for some variation 

 within the individual, there could not have been less than 18 or more 

 than 20 plates in the complete series. The greatest uncertainty yet 

 exists as to the exact number of cervical vertebrae. In the present 

 mount the first 12 vertebrae are considered as belonging to the neck, 

 thus leaving 15 of the 27 presacrals as pertaining to the thoracic 

 region. While the type of /S. stenops has a complete presacral series 

 present, unfortunately those at the junction of the neck with the 

 body are so crushed as to render them valueless for determining 

 this important point. The cervical ribs are also partially unknown 

 and it is not at all certain that as restored from scattered elements 

 they represent the true shape or show the exact transition in form 

 from the first to the last. 



»GUmore, C. W., Proc. U. S. Nat. Mus., vol. 49, 1915, p. 355. 

 3343— 19— Proc.N.M. vol.54 26 



