HISTORY OF DISCOVERY 



A brief resume of discoveries prior to 1907 should be given, although set forth in detail in the 

 Ceratopsia Monograph. 



Horned dinosaurs were first found in North America in 1855, when Dr. F. V. Hayden made a 

 geological reconnaissance on the Upper Missouri, around the mouth of the Judith River in Montana. 

 The material then collected, among which was a characteristic bi-fanged tooth subsequently referred 

 to Monoclonius, was described by Dr. Joseph Leidy in 1856 and 1859. In 1872, the form later 

 described by Prof. E. D. Cope as Agathaumas sylvestris was discovered by Prof. F. B. Meek at Black 

 Buttes Station on the Union Pacific Railroad 52 miles east of Green River, Wyoming. Cope him- 

 self visited the locality the same year and secured the remainder of the type. During the summer 

 of 1 873, Cope also discovered, somewhere in Colorado, the extremely fragmentary material which he 

 called Polyonax mortuarius. This is clearly ceratopsian, but Hatcher considered it so undiagnostic 

 that he rejected the genus and species as a nomen nudum, founded upon an insufficient type. Hatcher 

 further considered it possible that some of the material collected by Dr. G. M. Dawson on Milk 

 River, British America (? Alberta), should be referred to the Ceratopsia, although Cope himself 

 referred it to the trachodont Hadrosaurus. 



In 1876, Professor Cope, assisted by the veteran collector Charles H. Sternberg, explored the 

 Judith River badlands of the Upper Missouri in Montana. Much of the resultant material was 

 again too fragmentary for precise identification. It includes, nevertheless, the type of the ceratop- 

 sian Monoclonius crassus, as well as other specimens referable either to Monoclones or an allied 

 genus, and described in 1877. In 1890, after Marsh had made known the principal characters of 

 the Ceratopsia from abundant material collected by Hatcher in Wyoming and Montana, Cope was 

 able to describe three additional species from his Judith River collections. They were Monoclonius 

 recurvicornis, M. sphenocerus, and M. fissus. 



In 1887 Marsh described Bison alticornis, based upon a pair of horn cores found by Dr. George 

 L. Cannon in the Denver beds on Green Mountain Creek, near Denver, Colorado. The form was 

 subsequently referred to Ceratops, now Triceratops alticornis. For two or three years afterward, 

 Cannon, George H. Eldridge, and Whitman Cross continued to find fragmentary ceratopsians in the 

 Denver and Arapahoe beds, near Denver. This material has not yet revealed its true identity. 



Hatcher's own collecting under Professor Marsh's direction began in 1888 when he made col- 

 lections in the Judith River badlands, securing among other things the type of Ceratops montanus. 

 He then went to the eastern part of Converse County (now called Niobrara County), Wyoming, 

 where he was shown a massive horn core found on the ranch of Mr. Charles A. Guernsey by the 

 ranch foreman, Mr. Edmund B. Wilson. The next summer, Mr. Hatcher returned and secured 

 the remainder of the skull, which became his "skull number one," later known as the type of 

 Triceratops horridus; it was also the beginning of his highly successful exploration in this famous 

 Niobrara County locality, extending from 1889 to 1892, which yielded no fewer than 32 complete 

 or partial ceratopsian skulls and other skeletal material, including the types of most of the species of 

 Triceratops, two of Torosaurus, and one of Diceratops. All of these are now either in the United 

 States National Museum or in the Yale Peabody Museum. 



Another famous locality was in the region of the Milk, Red Deer, and Belly rivers of Alberta, 

 Canada, which were long known to contain dinosaurian remains. The systematic exploration of 

 this region was begun in 1897 by Lawrence M. Lambe and continued during the years 1898 and 



Finally, in 1902, an American Museum party consisting of Messrs. Barnum Brown and R. S. 

 Lull collected in Hell Creek, Montana, in Lance strata, a large Triceratops skull now in the American 

 Museum. 



