Dysganus encaustus, Cope, 1876

Cope, E. D., 1876, Descriptions of some vertebrate remains from the Fort Union beds of Montana, Proceedings of the Academy of Natural Sciences of Philadelphia 28, pp. 248-261 : 250-251

Dysganus encaustus , gen. et sp. nov.

Char. Gen. -A large number of teeth exhlibit the characters of this genus,which is a peculiar form of herbivorouis Dinosauria. The crowns are compressed, so that the tore and aft diameter much exceeds the transverse. The body of the crown is a flattenied shaft of dentine,one face of which is the denser, and produces the cutting edge. This face is flat or weakly keeled, whlie there are two other faces uniting at an open angle, thus giving a subtriangular section. On each of these faces is adherent a shaft of cementum-like material of a dense character, whose external face is lonigitudinally concave. These inclose between them on the median line a deep groove, which expands below into a wide concavity which appears to be enlarged as the age of the tooth increases preparatory to shedding. The other parts of the base of the crown below the cutting face, are inclosed in a rather thick deposit of rugrose cementum, which rises a distance on the sides of the tooth.

The method of replacement of the teeth in this genus appears to resemble that of Cionodon , except that there is no indication of the existence of as many series in the transverse direction. The longitudinal grooves in the anterior and posterior cement columns are probably occupied by the borders of the apices of successional teeth. The presence of these columns, etc, dlistinguishes this genus from that and other allied genera.

Char. Specif.--The cutting face is more or less concave, anid is impressed or sunken,its lateral borders, and the cement or the basis, projecting beyond it. The inferior bordeer is also usually oblique, that of one of the sides rising diagonally. In the same proportion, a weak keel is also unsymmetrically placed, lying close to the opposite border, and dividing the face into a wide and a narrow concavity. The oblique border is also incurved,the edge of the posterior cement column curving round the cutting face of the dentine. The latter is delicately rugose in unworn specimens. The external basal cementum rises highest on the incurved border of the crown; its surface is minutely rugose, the rugosity being generally punctiform. It is also of a different color from the dentine in the specimens as preserved, and is occasionially found nearly worn away. The edge of unworn teeth is not serrate.

Measurements.		M.
Length of basis of tooth		.012
Diameter of crown	antero-posterior	.009
	transverse	.004
Transverse diameter below crown		.008

The teeth are rather stnaller than those of Hadrosaurus foulkei . The borders present no indication of the crenation seen in that and other species, either in worn or unworn specimens.