cf. Edmontosaurus sp.

Figure 7

Material. — UCM 18953 pair of maxillae (Laramie Formation, Loc. 2).

Description and discussion. —A pair of hadrosaur maxillae is referred to Edmontosaurus sp. rather than Anatotitan because the ascending process of the maxilla is above the midpoint of the tooth row in Anatotitan; it is anterior to the midpoint in Edmontosaurus . Furthermore, the ratio of the length of the maxilla to the maximum height is greater in Anatotitan than in Edmontosaurus . These maxillae were mentioned previously by Toepleman (1935), Lull and Wright (1942), and Carpenter (1979).