Gryposaurus, LAMBE, 1914

Gates, Terry A. & Sampson, Scott D., 2007, A new species of Gryposaurus (Dinosauria: Hadrosauridae) from the late Campanian Kaiparowits Formation, southern Utah, USA, Zoological Journal of the Linnean Society 151 (2), pp. 351-376 : 352-353

GRYPOSAURUS LAMBE, 1914

Etymology: Derived from the Latin for ‘hooked beak’, intended by Lambe to reference the arch on the dorsal surface of the nasal, resembling a gryphin, and the Greek ‘ saurus ’ for lizard.

Revised diagnosis: Hadrosaurine hadrosaurids possessing the following autapomorphies: dorsolateral flare on the medial margin of the premaxillary lateral process; unexcavated nasal arch located anterior to the orbits; and sigmoidal nasofrontal suture characterized by a small median process of the nasal inserting between the midline of the frontals. Members of the genus also possess the following unique combination of characters: dorsoventrally deep skull; anterior process of nasal terminates along the dorsal margin of the external naris; ventral nasal process comprising approximately 25% of the ventral margin of the external nares; abbreviated circumnarial depression, extending posteriorly only as far as the lacrimal; jugal with large offset posteroventral flange, postorbital process at or near 90°, and narrow posterior process; and frontal contribution to the orbital rim.