Agathaumas

Agathaumas (; "great wonder") is a dubious genus of a large ceratopsid dinosaur that lived in Wyoming during the Late Cretaceous (late Maastrichtian stage, 66 million years ago). The name comes from - 'much' and - 'wonder'. It was seen as the largest land animal known at the time of its discovery.

It was the first ceratopsian known to science from more than teeth, though relatively little is known about it. The original specimen consisted only of the animal's hip bones, hip vertebrae and ribs, and because these bones vary little between ceratopsid species, it is usually considered a nomen dubium. It is provisionally considered a synonym of Triceratops or Torosaurus, but is difficult to compare to both genera because it is only known from postcranial remains.