



IsTO. 4. 



ON THE EXISTENCE OF DINOSAURIA IN THE TRANSITION 



BEDS OF WYOMING. 



By Edward D. Cope. 



During the present season, F. B. Meek, of Dr. F. V. Hayden's Geologi- 

 cal Survey of the Territories, discovered some large bones near Black 

 Buttes Station, on the Union Pacific Railroad, fifty-two miles east of 

 Green River, and near the Hallville Coal Mines. Shortly afterwards I 

 visited the spot with a branch expedition, and commenced excavations 

 with a view to the recovery of the remainder of the animal. The posi-. 

 tion was discovered to be between the thinner or lower strata of the 

 Bitter Creek series of coal, which at this point occupy a position of 

 elevation and crop out high on the bluffs. Two strata appear above the 

 sandstone in which the bones occur, and one below it. The portions of 

 the skeleton found, rested in the midst of vegetable debris, as sticks and 

 stems, and was covered with many beautiful dicotyledonous leaves, which 

 filled the interstices between the bones. The plant-bed gradually passed 

 into a shell-bed, containing numerous thin dimyaria, and close by, some 

 oysters were found. The whole question as to geologic age and aqueous 

 conditions during which these beds were deposited, being unsettled, I 

 gave especial attention to the recovery of the bones, with the view of 

 reaching a definite conclusion on these points. 



"We succeeded in recovering sixteen vertebrae, including a perfect 

 sacrum, with dorsals and caudals ; both iliac and other pelvic bones, 

 those of one side nearly perfect ; some bones of the limbs, ribs and other 

 parts not determined. 



The vertebras are large. The dorsals are short, with vertically oval 

 centra, and small neural canal. The diapophyses originate well above 

 the neural canal, diverge upwards, and are triangular in section. The 

 neural spine is very much elevated, and the arch short antero-pos- 

 teriorly. The zygapophyses are close together in both directions, those 

 of the same aspect being separated by a narrow keel only. They do not 

 project, but consist of articular surfaces cut into the solid spine. The 

 latter is flat and dilated distally. The articular faces are nearly plane 

 with a slight median prominence. 



The ribs have two articular surfaces, but I found no capitular pit on 

 the dorsal centra. 



Elevation of centrum, 7.5 in. ; width of the same, 5 in. 7.5 lines ; length 

 of do., 3 in. 8.5 lines. Total elevation of a dorsal vertebra, twenty-eight 

 inches three lines. The sacrum consists of five vertebras, the anterior 

 centrum not depressed. They give out huge diapophyses which are 

 united by suture. They are themselves united distally in pairs, each 

 pair supporting a longitudinal convex articular face for the ilium. Each 

 pair encloses a perforation with the centra. The first diapophysis goes 

 off from the point of junction of the first and second vertebrae, the second 

 from the third only, and is more slender. The total length is 25 in. ; 



