The chasmosaurs were the second major branch of the ceratopsids, and ranged throughout most of western North America from Mexico to Canada during the end portion of the Cretaceous (~78-66 mya). They tended to have larger brow horns than their centrosaur cousins, and more elongated frills that lacked elaborate spikes.
Mercuriceratops (“Mercury horned face”) was one of the earliest chasmosaurs, living in Alberta, Canada and Montana, USA about 77 million years ago. Known only from two almost-identical skull fragments found on each side of the Canada-USA border, its full body size is uncertain – but estimates range from 4 to 6m (13′-19′8″).
It had prominent projections on the sides of its frill, forming distinctive “wing” shapes unlike any other known ceratopsid.
The rest of its ornamentation is still unknown, but it was likely similar to other early chasmosaurs like Judiceratops, with moderately-sized brow horns and a small nose horn.