APPENDIX.
Art. XIV.—Description Of New Dinosaurian Reptiles by O. C. Marsh. (With Plate 1.)
Recent explorations in the West have resulted in the discovery of many remains of Dinosaurs, some of which are of more than ordinary interest. A few are from the Jurassic, but most of them are from the Cretaceous, especially from the upper portion, in the so called Laramie formation. Those found in the latter horizon show a high degree of specialization, and present some anatomical features not before observed in this group of reptiles. Several of the new forms are briefly described below, and will be more fully discussed in a later communication.
Triceratops serratus, sp. nov.
First in importance of the new discoveries is a nearly perfect skull of the genus Triceratops, a typical example of which (T.flabellatus) was described and figured by the writer in the last number of this Journal.[1] The present skull is more perfect than any hitherto found, and exhibits admirably the strongly marked characters of the genus. It is likewise of gigantic size, being nearly six feet in length (1.8m), although the animal was not fully adult.
A striking peculiarity of this skull, which has suggested the specific name, is a series of bony projections on the median line of the parietal crest. The latter is elevated along this line to support them, and the sides descend rapidly to their union with the squamosals. There is a second series of elevations along the middle of the squamosal bone as it falls away from the base of the horn-core, but these are much less prominent.
The orbit is nearly circular in form, instead of oval, and is situated above, and forward of its position in the species referred to. The quadrato-jugal meets the anterior process of the squamosal, forming a closer union than in the skull previously figured. In this respect, and in the elevations on the squamosal, it approaches a much smaller specimen at present referred to the genus Ceratops.
- ↑ This Journal, vol. xxxviii, pp. 501-506, December, 1889.
Am. Jour. Sci.-Third Series, Vol. XXXIX, No. 229.-Jan., 1890.
