Achelousaurus

dinosaur · ceratopsid · Late Cretaceous · Montana

Strange Head Shape. Achelousaurus had an unusual bumpy crest on its head instead of a tall pointed horn like its relatives. Scientists think these bumps might have been used to show off to other dinosaurs or recognize each other.

Montana Discovery. The first Achelousaurus fossils were found in Montana in 1987 by a famous dinosaur hunter named Jack Horner. More bones were discovered in 1989, giving scientists a better picture of this dinosaur.

Named in 1994. The dinosaur was officially named Achelousaurus horneri by scientist Scott Sampson. The name comes from a Greek water god called Achelous, and horneri honors Jack Horner for his discovery work.

Many Life Stages. Scientists have found Achelousaurus fossils from young juveniles all the way to full-grown adults. Most of what we know comes from their skull bones, which tell us a lot about how they looked and grew.

Ancient Relative. Achelousaurus lived during the Late Cretaceous Period, about 77 to 75 million years ago. This was near the very end of the dinosaur age, before the great extinction event.