26 



LARAMIE FLORA OF THE DENVER BASIN. 



1872 at Black Buttes, Wyo., by F. B. Meek, 

 and later in the same year collected by Cope 

 himself. (See p. 8.) In the following year 

 Cope 90 found the -remains of what is now known 

 to be a member of this group at some uniden- 

 tified locality in Colorado, and in 1876 he un- 

 dertook the exploration of the Judith River 

 region, describing a number of remains that 

 from their fragmentary nature he was not able 

 to allocate until the group had been made better 

 known from the studies of O. C. Marsh. • 



As already mentioned (p. 16), the remains 

 of horned dinosaurs, although not at first so 

 recognized, were found by Lakes, Cross, El- 

 dridge, Cannon, and others in the post-Lara- 

 mie beds of the Denver Basin of Colorado 

 during the period extending from 1881 to about 



1887. These were described in part by Marsh. 

 In the summer of 1888 J. B. Hatcher, then 

 assistant to Marsh, found the poorly preserved 

 remains of a dinosaurian in Wyoming just 

 north of the Seminoe Mountains, on the west 

 side of North Platte Eiver about 40 miles 

 below Fort Steele. 



The above brief account completes the list 

 of discoveries of remains of the Ceratopsia that 

 fall within the present discussion prior to the 

 finding of the celebrated deposits in Converse 

 County, Wyo. These deposits were made 

 known late in the fall of 1888, when a single 

 horn core was brought to the attention of Mr. 

 Hatcher by a resident of the region. This dis- 

 covery was considered so important by Marsh 

 that Hatcher was directed to return to the 

 region at the earliest moment, which was in 

 January, 1889, and from this time until 1895 

 Hatcher was almost continuously employed in 

 exploring and collecting from these rich de- 

 posits. The material he obtained, which was 

 very extensive and varied, furnished the basis 

 for a series of important papers by Marsh. 



Before proceeding to the discussion of the 

 Converse County area and its bearing on the 

 question under consideration, it may be well 

 to point out that the family Ceratopsidae,, 

 which has become so important in this connec- 

 tion, was established by Marsh 91 in December, 



1888. The exact locality' that yielded the 

 specimen on which this family was based was 



»o Cope, B. D., Report on the vertebrate paleontology of Colorado: 

 U. S. Geol. and Geog. Survey Terr. Ann. Kept, for 1873, p. 429, 1874. 



» Marsh, O. C, A new family of horned Dinosauria, from the Creta- 

 ceous: Am. Jour. Sei., 3d ser., vol. 36, p. 478, 1888. 



not recorded by Marsh, who said it "was found 

 in place, in Laramie deposits.of the Cretaceous, 

 in Montana, " and added in the next paragraph: 

 "Remains of the same reptile, or one nearly 

 allied, had previously been found in Colorado, 

 in deposits of about the same age." Accord- 

 ing to Hatcher 92 the beds of the Montana 

 locality were near the top of the Judith River 

 formation on Cow Creek, 10 miles above its 

 confluence with the Missouri. The Colorado 

 specimen referred to came from the Arapahoe 

 formation of the Denver Basing 3 



Marsh's first paper M dealing with what is 

 now known to be the Converse County material 

 was published in April, 1889, and describes 

 some Jurassic forms and a single specimen 

 from this region. This was named Ceratops 

 horridus, and in August of the same year it 

 was made the type of the genus Triceratops. 95 

 Incidentally it may be, mentioned that this 

 genus was based in part on the horn core first 

 known from these beds as noted by Hatcher. 

 In neither of these papers is there mention of 

 the locality beyond the statement that the 

 remains came from "the Laramie formation 

 of Wyoming. " 



In December, 1889, a third paper by Marsh 96 

 was published, in which, in addition to describ- 

 ing the skull more in detail, he gave the follow- 

 ing brief statement on the geologic occurrence 

 of the Ceratopsidae : 



The geological horizon of these strange reptiles is a 

 distinct one in the upper Cretaceous and has now been 

 traced nearly 800 miles along the eastern flank of the 

 Rocky Mountains. It is marked almost everywhere by 

 remains of these reptiles, and hence the strata containing 

 them ma/ be called the Ceratops beds. They are fresh- 

 water or brackish deposits, which form a part of the so- 

 called Laramie but are below the uppermost beds referred 

 to that group. In some places, at least, they rest upon 

 marine beds which contain invertebrate fossils character- 

 istic of the Fox Hills deposits. 



In commenting on this statement a few 

 years later, Cross 97 said : 



» s Hatcher, J. B., The Ceratopsia: U. S. Geol. Survey Mon. 49, p. 101, 

 1907. 



» Cross, Whitman, Geology of the Denver Basin of Colorado: TJ. S. 

 Geol. Survey Mon. 27, p. 230, 1896. 



" Marsh, O. C, Notice of new American Dinosauria: Am. Jour. Sci., 

 3d ser., vol. 37, p. 331, 1889. 



» Marsh, 0. C-., Notice of gigantic horned Dinosauria from the Creta- 

 ceous: Am. Jour. Sci., 3d ser., vol. 38, p. 173, 1889. 



e« Marsh, O. C, The skull of the gigantic Ceratopsidae: Am. Jour. Sci., 

 3d ser., vol. 38, pp. 501-506, 18"89. 



91 Cross, Whitman, Geology of the Denver Basin of Colorado: TJ. S. 

 Geol. Survey Mon. 27, p. 231, 1896. 



