Tyrannosaurus rex Osborn, 1905

Figs. 2A, 3, 5A

= Dynamosaurus imperosus Osborn 1905

Holotype: CM 9380 (formerly AMNH 973) partial skull and skeleton from the Hell Creek Formation, Montana, U.S.A .

Diagnosis: Angular terminates posterior to the surangular fenestra. Surangular fenestra much larger than in Tyrannosaurus bataar . Maxilla terminates below the lacrymal.

Stratigraphic and Paleobiogeographic Distribution: Scollard and Willow Creek formations of Alberta; Frenchman Formation of Saskatchewan; Hell Creek Formation of Montana, North Dakota, and South Dakota; Lance Formation of Wyoming; and Laramie Formation of Colorado.