Gilmore (1946) described an almost complete skull of a small tyrannosaur as Albertosaurus lancensis . Bakker et al. (1988) recognized the differences of this skull to other material of Albertosaurus, and proposed the new generic name Nanotyrannus . However, Carr (1999) argued that the type of
Nanotyrannus
represents a juvenile individual of
Tyrannosaurus rex
. This view is followed here.