Prodesmodon copei Estes, 1964

Prodesmodon copei is represented in the Judith River Formation by a number of dentaries and maxillae from Clambank Hollow. Although all the specimens are distinctly smaller than those from the Lance Formation figured by Estes (1964, pp. 90, 91), they are included in the same species. Morphology of the dentary and the form of the teeth is exceedingly similar in specimens from the two formations. As the present dentaries are incomplete, it is impossible to count the teeth on the lower jaw but the number appears to be less in the Campanian specimens. The teeth are pleurodont and vary considerably in size. The front teeth in AMNH 8479, except for the anteriormost two or three, are quite large (height 0.8 mm.) as compared with the teeth in the posterior part of the dentary. Enlargement of the anterior teeth is accompanied by a corresponding deepening of the jaw. A small foramen is present at the base of each tooth. Externally, the dentary is smooth and is strongly curved in dorsal view.