Monoclonius-life restoration

Monoclonius ("single sprout") is a dubious genus of centrosaurine ceratopsids from the late Cretaceous period, closely related to Centrosaurus and Styracosaurus. Their faces bore a single horn, and their frills did not bear any remarkable ornamentation.

In The Land Before Time

A Monoclonius appears in The Land Before Time VIII: The Big Freeze as one of the dinosaurs seen in the crowd in Mr. Thicknose's flashback during the song 'The Lesson'.