APPENDIX 



Aet. XXXIX. — Restoration of Triceratops ; by O. C. Marsh. 

 (With Plates XV and XYI.) 



In previous numbers of this Journal, the writer has given 

 the principal characters of the gigantic Ceratopsidw, or horned 

 Dinosaurs, from the Laramie, with figures of the more import- 

 ant parts of the skull and skeleton.* The abundant material 

 now available for examination makes it possible to attempt a 

 restoration of one characteristic form, and the result is given 

 in Plate XY. This figure, about one-fortieth of natural size, 

 is reduced from a large outline plate of a memoir on this 

 group, now in preparation by the writer for the United States 

 Geological Survey. 



This restoration is mainly based on two specimens. One of 

 these is the type of Triceratops prorsus, Marsh, in which the 

 skull, lower jaw, and cervical vertebrse are in remarkable 

 preservation. The other specimen, although somewhat larger, 

 is referred to the same species. It consists of parts of the 

 skull, of vertebrae, the pelvic arch, and nearly all the important 

 limb bones. The remaining portions are mostly taken from 

 other remains found in the same horizon and localities, and at 

 present are not to be distinguished specifically from the two 

 specimens above mentioned. The skull as here represented 

 corresponds in scale to the skeleton of the larger individual. 



In this restoration, the animal is represented as walking, and 

 the enormous head is in a position adapted to that motion. The 



* This Journal (3), vol. xxxvi, p. 477, December, 1888; vol. xxxvii, p. 334, 

 April, 1889; vol. xxxviii, p. 173, August, 1889, p. 501, December, 1889; vol. 

 xxxix, p. 81, January, 1890, p. 418, May, 1890; and vol. xli, p. 167, Febrnarv, 

 1891. 



Am. Jour. Sci. — Third Series, Vol. XLI, No. 244. — April, 1891. 

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