 The first remains of tyrannosaurids were uncovered during expeditions led by the Geological Survey of Canada , which located numerous scattered teeth . These distinctive dinosaur teeth were given the name Deinodon ( " terrible tooth " ) by Joseph Leidy in 1856 . The first good specimens of a tyrannosaurid were found in the Horseshoe Canyon Formation of Alberta , and consisted of nearly complete skulls with partial skeletons . These remains were first studied by Edward Drinker Cope in 1876 , who considered them a species of the eastern tyrannosauroid Dryptosaurus . In 1905 , Henry Fairfield Osborn recognized that the Alberta remains differed considerably from Dryptosaurus , and coined a new name for them : Albertosaurus sarcophagus ( " flesh @-@ eating Alberta lizard " ) . Cope described more tyrannosaur material in 1892 , in the form of isolated vertebrae , and gave this animal the name Manospondylus gigas . This discovery was mostly overlooked for over a century , and caused controversy in the early 2000s when it was discovered that this material actually belonged to , and had name priority over , Tyrannosaurus rex . 
