In the November 1990 (Vol. 64, no. 6) issue of the Journal of Paleontology, Lehman and Carpenter described an Aublysodon, which at the time was believed to be the most complete Carnosaur known from the Upper Cretaceous Kirtland Shale of northwestern New Mexico. Recently, a more complete specimen, considered to be a tyrannosaurid dinosaur on the basis of a proximally constricted third metatarsal and a partial D-shaped (in cross section) premaxillary tooth (Molnar, 1990), has been brought to the attention of the Museum of Geology at Arizona State University by an amateur paleontologist who recognized its scientific importance after obtaining it from an individual in New Mexico. The remains of this dinosaur, collected in northwestern New Mexico sometime in late 1989 or early 1990 by unknown persons, include both cranial and skeletal material (Figure 1.1).