Albertosaurinae

Albertosaurines, or dinosaurs of the subfamily Albertosaurinae, lived in the Late Cretaceous of United States and Canada. The subfamily was first used by Philip J. Currie, Jørn H. Hurum, and Karol Sabath as a group of tyrannosaurid dinosaurs. It was originally defined as "(Albertosaurus + Gorgosaurus)", including only the two genera. The group is the sister clade to Tyrannosaurinae. In 2007, it was found that the group also contained Maleevosaurus, often synonymized with Tarbosaurus. However, this classification has not been accepted and Maleevosaurus is still considered a juvenile Tarbosaurus or Tyrannosaurus.

==Description== Albertosaurines are large, lightly built tyrannosaurids. Compared to tyrannosaurines, they are more slender and have shorter, flatter skulls, shorter ilia, and proportionally longer tibiae. Albertosaurines and tyrannosaurines share arms of about equal length, with the exception of Tarbosaurus, which had short arms for its size. thumb|left|Size comparison of Albertosaurus ([[yellow) with Gorgosaurus (blue) and a human]] Albertosaurus was smaller than some other tyrannosaurids, such as Tarbosaurus and Tyrannosaurus. Typical adults of Albertosaurus and Gorgosaurus measured up to long, while rare individuals of Albertosaurus could grow to over in length. Several independent mass estimates, obtained by different methods, suggest that an adult Albertosaurus weighed between and . Gorgosaurus estimates are higher, around , although greater estimates exist of about .