Bonaparte et al. (1990) indicated their first used Tyrannosauroidea and were credited accordingly by Sereno (1998). Walker (1964), however, was first to use the superfamily in his classification that included the families Ornithosuchidae, Tyrannosauridae, and Spinosauridae.
Tyrannosauroidea was first defined by Sereno (1998) as a stem-based definition to include all members of this increasingly diverse stem clade. Sereno (1998) only used Neornithes as an external specifier. Holtz (2004) use Ornithomimus velox, Deinonychus antirrhopus, and Allosaurus fragilis. The critical external specifiers are those that represent clades that could conceivable be related to tyrannosauroids, and these include ornithomimosaurs, troodontids, and dromaeosaurids. There is really no need to include Allosaurus or Passer as external specifiers, as no recent cladogram considers Aves or Allosauroidea close relatives of tyrannosauroids. The active definition is a first-order revision of both previous definitions (Sereno 1998, Holtz 2004).