Gryposaurus, meaning "hooked-nosed lizard" (derived from the Greek "grypos"), was a duckbilled dinosaur genus that roamed North America around 80 to 75 million years ago during the Late Cretaceous period, specifically spanning the late Santonian to late Campanian stages. Species belonging to Gryposaurus have been identified in the Dinosaur Park Formation in Alberta, Canada, and in two formations within the United States: the Lower Two Medicine Formation in Montana and the Kaiparowits Formation in Utah. There's also a potential additional species from the Javelina Formation in Texas that could extend the temporal range of the genus to 66 million years ago.

Numerous Gryposaurus specimens, including skulls, some skeletons, and even skin impressions, provide insights into its physical characteristics. These fossils reveal the presence of pyramidal scales projecting along the midline of its back. What truly sets Gryposaurus apart from other duckbills is its distinctive, narrow, arching nasal hump, often likened to a "Roman nose." This feature may have served purposes like species or sexual identification and possibly combat with individuals of the same species.

This large herbivore, which could switch between bipedal and quadrupedal locomotion, measured around 8 meters (26 feet) in length and likely favored river environments. As a hadrosaurid, Gryposaurus primarily consumed plant material, with its specialized skull joints enabling a chewing-like grinding motion. Its teeth continuously replaced and were packed into dental batteries containing hundreds of teeth, though only a small number were actively used. The dinosaur's broad beak was suited for cropping plant material, which it held in its jaws using a cheek-like organ. Gryposaurus had a feeding range spanning from ground level up to about 4 meters (13 feet) above it.

The distinctive nasal arch of Gryposaurus, like other cranial modifications seen in duckbills, may have served various social functions such as distinguishing sexes or species and indicating social hierarchy. It might have also functioned as a tool for pushing or butting in social interactions, potentially featuring inflatable air sacs for visual and auditory signaling. In some specimens, the top of the arch appears roughened, suggesting it could have been covered by thick, keratinized skin or featured a cartilaginous extension.