An Abertosaurus is the main antagonist in The Land Before Time VIII: The Big Freeze.
He was first seen at the beginning of the film attacking several dinosaurs, including a hadrosaur, but fails every time.
After a long absence, he attacked Ducky and follwed her all to her friends including Mr. Thicknose.
It was knocked out by a giant snowball Littlefoot and his friends made. The dinosaur made it's last appearance in the movie attacking littlefoot and his friends, Mr. Thicknose saved the kids by pushing an old tree down the hill. Albertosaurus slid on the log and fell down the cliff.
He was probably killed by the fall. It is similar to a T-Rex.