Prosaurolophus

Prosaurolophus was a duck-billed dinosaur that lived in western North America during the Late Cretaceous, approximately seventy-six million years ago. Named by Barnum Brown due to its resemblance and evolutionary precedence to Saurolophus, it is well known from abundant skeletal material unearthed in Alberta and Montana. It was an eight-metre-long herbivore with a robust skull featuring a low, solid, rugose crest situated between its eyes. Deep depressions in front of the orbits suggest that Prosaurolophus possessed inflatable nasal soft tissues, which could have amplified sounds or flashed bright colours during social interactions. Like all hadrosaurids, it spent much of its time feeding on fibrous shrubs, twigs, and ferns, moving comfortably on all four limbs while using its muscular hind limbs for rapid flight if threatened by predators such as gorgosaurs.

It had a small, blunt forehead crest directly ancestral in form to the prominent backward spike of Saurolophus.

Where and when

Prosaurolophus lived in the Late Cretaceous, from 76.5 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 m (estimates run from 7.5 to 8.5 m). Mass about 3 t. Hip height about 2.6 m. That is 4.7 human-lengths, or 0.71 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

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