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THE CERATOPSIA. 143 



STERRHOLOPHUS Marsh. 1891. 



Type species, <S. flabellatus. 



Original description in Am. Jour. Sci., 3d ser., vol. 41, April, 1891, p. 340. 

 Marsh, O. C, Am. Jour. Sci., 3d ser., vol. 43, Jan., 1892, pp. 83 and 84; vol. 50, Dec, 1895, p. 497; Sixteenth Ann. Rept. 



U. S. Geol. Survey, 1896, pt. 1, pp. 216-217, 243. 

 Nopcsa, F. Baron, Foldtani Kozlony, Budapest, 1901, vol. 31, p. 270. 

 Osborn, H. F., Contr. Canadian Pal., vol. 3 (quarto), pt. 2, 1902, pp. 20, 21. 

 Woodward, A. S., Outlines Vert. Pal., pp. 213, 216. 

 Zittel, K. A. von, Text-Book Pal., transl. by C. R. Eastman, vol. 2, p. 245. 



In publishing his restoration of Triceratops in the American Journal of Science of April, 

 1891, Marsh proposed the new genus Sterrholophus. He based this genus on the skull of a 

 young individual which he had previously (Am. Jour. Sci., 4th ser., vol. 8, Aug., 1899, p. 174) 

 made the type of a new species of Triceratops (T. flabellatus). This now became the type of 

 the genus Sterrholophus. The following paragraph by Marsh relating to the generic distinctions 

 between the genera Triceratops, Ceratops, and Sterrholophus is worth quoting in this connection. 

 He says: 



This restoration gives a correct idea of the general proportions of the entire skeleton in the genus Triceratops. The size 

 in life would be about 25 feet in length and 10 feet in height. The genus Ceratops so far as at present known is represented 

 by individuals of smaller size and, in some instances, at least, of quite different proportions. A third genus, which may be 

 called Sterrholophus, can be readily distinguished from the other two by the parietal crest, which had its entire posterior 

 surface covered with the ligaments and muscles supporting the head. In Ceratops and Triceratops a wide margin of this 

 surface was free and protected by a thick, horny covering. 



In writing the above lines Professor Marsh appears to have forgotten that the parietal 

 crest of Geratops was quite unknown, and that therefore it was uncertain as to whether in that 

 genus the parietal crest was free and protected by a horny covering or covered over with liga- 

 ments and muscles. Another point which does not seem to have been sufficiently considered 

 by Marsh in establishing this genus is the immature nature of the skull upon which it is based. 

 Considering the youth of the individual it does not appear at all improbable that if the parietal 

 crest had been free, as in Tnceratops, it would have shown those rugosities and other features 

 so prominent on the surface of these bones in the skulls of older and more mature individuals. 

 Then, again, if these characters are present in some and absent in other skulls of adult animals 

 should they be considered as of generic or even specific importance or as sexual characters? 

 These questions will be discussed more in detail in the revision of the genera and species. 



Sterrholophtjs flabellatus Marsh. 1889. 



Type (No. 1821, Yale Museum) consists of a nearly complete but disarticulated skull associated with several vertebra;, 



a few limb bones, etc. 

 Original description of type in Am. Jour. Sci., 3d ser., vol. 38, Aug., 1889, p. 174, where it is referred to Triceratops. 

 Made the type of the genus Sterrholophus in Am. Jour. Sci., 3d ser., vol. 41, April, 1891, p. 340. 

 Marsh, O. C, Am. Jour. Sci., 3d ser., vol. 43, Jan., 1892, p. 84; Mon. U. S. Geol. Survey, vol. 27, 1897, p. 511. 

 Nopcsa, F. Baron, Foldtani Kozlony, Budapest, 1901, vol. 31, p. 270. 

 Osborn, H. F., Contr. Canadian Pal., vol. 3 (quarto), pt. 2, 1902, p. 14. 

 Woodward, A. S., Outlines Vert. Pal., p. 215. 

 Zittel, K. A. von, Text-Book Pal., transl. by C. R. Eastman, vol. 2, p. 245. 



ORIGINAL DESCRIPTION. 



Professor Marsh's original description of this species was as follows: 



Triceratops flabellatus, sp. nov. 



A second specimen of still greater dimensions has since been found at another locality of the same formation by Air. J. B. 

 Hatcher. The skull, lower jaws, and a considerable portion of the skeleton were found together. A striking peculiarity of 

 this skull is the occipital crest, which extends upward and backward, like an open fan. Its margin was armed with a row of 

 horny spikes, supported by separate ossifications, some of which were found in position. 



The skull as it lay in the rock measured more than 6 feet in length, 4 feet in width, and the horn cores about 3 feet in 

 height. These dimensions far surpass any of the Dinosauria hitherto known, and indicate to some extent the wonderful 

 development these reptiles attained before their extinction at the close of the Cretaceous. 



As already noted, two years later Marsh removed this species from the genus Triceratops 

 and made it the type of the new genus Sterrholophus. 



