Henry Fairfield Osborn, president of the American Museum of Natural History, named the Tyrannosaurus Rex in 1905.  The generic name is derived from the Greek words tyrannos, meaning “tyrant” and sauros, meaning “lizard”.  Osborn used the Latin word rex, meaning “king”, for the specific name. The full binomial therefore translates to “tyrant lizard the king” or “King Tyrant Lizard”, emphasizing the animal’s size and perceived dominance over other species of the time.