Trachodon mirabilis, Leidy, 1856

Leidy, J., 1856, Notice of remains of extinct reptiles and fishes, discovered by Dr. FV Hayden in the Bad Lands of the Judith River, Nebraska Territory., Proceedings of the Academy of Natural Sciences of Philadelphia 8, No. 7, pp. 72-73 : 72

2. Trachodon mirabilis , Leidy.

The genus and species are founded upon specimens of teeth, generally very much worn and in a fragmentary condition, of a herbivorous lacertian reptile allied to the Iguanodon , discovered by Dr. Hayden.

One of the specimens of teeth is an unworn crown, about 14 lines long and 5 lines in diameter at its thickest part. It has the form of a slightly bent hexahedral column, bevelled off convexly from the summit of the tooth internally to the base externally. The outer surface is smooth, and has a prominent median ridge and prominent subacute lateral borders. The inner surface of the tooth, presenting the five smaller sides of the column, is quite roughened with irregular granulations. The base of the tooth is hollow, and its walls at the broken border of the specimen are l1/2 lines thick.

In another and much worn specimen of a tooth, which had apparently been shed, and is now 4 1/2 lines long; the triturating surface is slightly concave and pentahedral, with concave sides, and is 4 lines in diameter. The two portions of the outer surface incline much more from the median ridge than in the preceding specimen; and the base of the tooth is hollowed, apparently from the pressure of a successor.