tyrannosaurus (n.)

carnivorous Cretaceous bipedal dinosaur, 1905, Modern Latin genus name, coined by H.F. Osborn (published 1906 in "Bulletin of the American Museum of Natural History" XXI, p.259) from Greek tyrannos "tyrant" (see tyrant) + -saurus. Abbreviated name T. rex attested by 1970 (apparently first as the band name).