A partial skeleton of the tyrannosaurid dinosaur Aublysodon from the Upper Cretaceous of New Mexico

Abstract

A fragmentary tyrannosaurid skull and postcranial skeleton from the Kirtland Shale of northwestern New Mexico is the most complete specimen of a carnivorous dinosaur known from these strata. The specimen is identified as Aublysodon cf. A. mirandus on the basis of its narrow frontals, V-shaped frontal-parietal suture, and nondenticulate incisiform premaxillary tooth. The D-shaped cross section of the premaxillary tooth, rugose postorbital, well-developed footed pubis, and proximally constricted third metatarsal confirm the assignment of Aublysodon to the Tyrannosauridae. The limb bones are gracile and similar in proportions to those of Albertosaurus; however, the tibia and metatarsals are shorter relative to the femur. The distal end of the tibia exhibits a unique medial emargination not reported in other tyrannosaurids.