"Rough Three Horned Face"
Length: 9m (30ft)
Weight: 5.8 tonnes (6.5 tons)
Location: Colorado, USA
Era: Maastrichtian age, upper Cretaceous (65 million years ago)
When Marsh first saw the original specimen, he had mistakenly thought that it came from Pliocene rocks, and considered it an unusual type of bison.