[D] Albertosaurus lancensis [Su]
Cretaceous Late Maastrichtian
Saurischia Theropoda Tyrannosauria Tyrannosauridae Tyrannosaurinae Albertosaurini
Hell Creek Formation, Montana, US
Nanotyrannus (Bakker, Currie & Williams, 1988) > Nanotyrannus lancensis (Gilmore, 1946) = Albertosaurus (Clevelanotyrannus) lancensis (Gilmore, 1946 vide Paul, 1988) > Gorgosaurus lancensis (Gilmore, 1946) >> Clevelanotyrannus (Bakker, Williams & Currie vide Currie, 1987) Albertosaurus lancensis (Russell, 1970) Albertosaurus (Nanotyrannus) lancensis (Gilmore, 1946 vide Paul, 1988)
Renamed species originally described by Charles Whitney Gilmore in 1946 as Gorgosaurus lancensis; referred to the subgenus Albertosaurus by Dale Alan Russell in 1970.
Nanotyrannus was found in Montana by a museum curator in 1942. It was first described as a new species of Gorgosaurus and later reclassified as an Albertosaurus lancensis. Other scientists suggested that the small skull came from a juvenile Tyrannosaurus rex. In the late 1980s re-evaluation of the skull, which has some odd features are its wedge shape, narrow beak, and huge crest on top, led to the conclusion that the skull belonged to a primitive, but new and separate tyrannosaurid genus which they named Nanotyrannus, or \\\\\\\"pygmy tyrant,\\\\\\\".
A CAT scan, which revealed an unusual feature of one skull bone not seen in other tyrannosaurs, bolstered the claim that this specimen was something different.