Alioramus remotus, Kurzanov, 1976

Holtz, TR jr., 2004, Tyrannosauroidea, The Dinosauria, University of California Press, pp. 111-136 : 2-3

Alioramus remotus

is a problematic tyrannosaurid known only from a partial skull and associated metatarsals from the Nogoon Tsav beds of the Ingenii Höövör valley, Mongolia (Kurzanov 1976b). The reconstruction of Kurzanov (1976b) fails to correct for dorsolateral crushing of the braincase; the restoration in Paul (1988a) corrects for this and uses a short rather than a pointed premaxilla. The skull length is estimated at approximately 45 cm (Currie 2000).

In some ways this taxon is primitive, retaining a high tooth count, a low snout, and a long, slender dentary. However, the ontogenetic stage of this individual is uncertain, and these features are found in juveniles of other tyrannosaurs, only to be lost in adulthood (Carr 1999; Currie 2003b). Alternatively, it shares many attributes with tyrannosaurines in general, and with Tarbosaurus and Tyrannosaurus it shares a transverse nuchal crest that is rostrocaudally thick with a rugose dorsal margin; reduced basal tubera, smaller than the ventral ends of the basipterygoid processes; and an occipital region directed caudoventrally. With Tarbosaurus in particular it shares the lack of a caudally oriented lacrimal process. Hurum and Sabath (2003) suggest that Tarbosaurus and Alioramus may be sister taxa, and Hurum (pers. comm.) suggests that they may form a clade to the exclusion of the North American tyrannosaurids. Previously described differences between the braincase of this dinosaur and that of other tyrannosaurids (Kurzanov 1976a; Holtz 2001b) have proven spurious (Currie 2003a). Currie (2003a) suggests that “ Alioramus ” might be a juvenile Tarbosaurus but notes that the higher tooth count and the prominence of the nasal crests make this improbable.

The following four taxa represent species not examined phylogenetically for this analysis but for which there is some tentative evidence for a position within Tyrannosauroidea but almost certainly outside of Tyrannosauridae .