Scolosaurus is an extinct genus of ankylosaurid dinosaurs within the subfamily Ankylosaurinae. It is known from either the lower levels of the Dinosaur Park Formation or upper levels of the Oldman Formation (the location of the type specimen's quarry is uncertain) in the Late Cretaceous (latest middle Campanian stage, about 76.5 Ma ago) of Alberta, Canada. It contains a single species, Scolosaurus cutleri. It is the oldest known North American anklylosaurid.
For a long time, it was considered synonymous with Euoplocephalus, but following research eventually found both dinosaurs to be separate genera.
In The Land Before Time[]
Rooter, a character from The Land Before Time, appears to be based on some depictions of Scolosaurus from the time the film came out, though whether or not he is actually intended to be a Scolosaurus is unknown.