Gryposaurus

Gryposaurus was an iconic Campanian duck-billed dinosaur known from multiple species discovered across western North America, spanning from Alberta south to Utah. Reaching around eight to nine metres in length, it was characterised by its conspicuous hook-nosed appearance, formed by a prominent bony arch along the nasal bones just in front of the eyes. This structure likely served as a display organ and may have housed inflatable soft-tissue sacs. Numerous beautifully preserved specimens have yielded extensive information on Gryposaurus anatomy, including patches of preserved skin revealing irregular polygonal scales and a row of pyramidal midline scales running down its back. Its efficient grinding dentition permitted it to feed on a wide variety of tough terrestrial vegetation, which it processed while moving on all four legs or occasionally browsing bipedally.

Its prominent nasal arch gave it a distinctive Roman nose profile used for species recognition.

Where and when

Gryposaurus lived in the Late Cretaceous, from 80.5 to 74.5 million years ago (Campanian age). Its remains come from Canada and United States, in the Dinosaur Park Formation.

The numbers

Length 8.5 m (estimates run from 8 to 9 m). Mass about 3.5 t. Hip height about 2.8 m. That is 5 human-lengths, or 0.76 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Gryposaurus with a bus Place on the timeline