Monoclonius crassus, 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 : 255-256

Monoclonius crassus , gen. et sp. nov.

Char. Gen. - Teeth with obliquely truncate face and distinct root, which is grooved for the successional tooth on the front. No external cementum layer, caudal vertebrae biconcave, and brim narrow. Fore limbs large and massive.

The teeth of this genus resemble those of Hadrosaurus , and like them, are replaced from the "'front, " an arrangement which precludes the possibility of more than one series of teeth being in fuinctional use at one time. The robust fore limibs and elongate ilium distinguish Diclonius from Hadrosaurus. From Trachodon it differs in the absence of the rough cementum layer on the back of the tooth.

Char. Specif. -The faces of the teeth are acuminate oval in form, and are divided by an elevated keel, which is median above, but turns to one side at the base. Margin crenate, the grooves extending more or less on the convex " back, " which is otherwise smooth.

Sacrum with ten vertebrae, the last centrum much compressed, the diapophyses extending horizontally from the neutral arch above, and connected by a vertical laminia with the iliac supports; length 27.33 inches. The bones of the limbs are robust, the hinder the longer, but not so much so as in some other genera. Length of femur 22 inches; width, proximally, 7.4 inches; distally 6 inches. Length of tibia 20 inches; greatest diameter, proximally, 8 inches; distally 7.25 inches. The three anterior dorsal vertebrae are coossified, and the first exhibits a deep cup for articulation with the preceeding vertebra. The episternum is a T-shaped bone, thin and keeled on the median line below. Length of transverse portion 21 inches.