|1.||saurischian See also ornithischian pterosaur Compare plesiosaur any extinct terrestrial reptile of the orders Saurischia and Ornithischia, many of which were of gigantic size and abundant in the Mesozoic era|
|2.||a person or thing that is considered to be out of date|
|[C19: from New Latin dinosaurus, from Greek deinos fearful + sauros lizard]|
dinosaur [%PREMIUM_LINK%] (dī'nə-sôr') Pronunciation Key |
Any of various extinct reptiles of the orders Saurischia and Ornithischia that flourished during the Mesozoic Era. dinosaurs were carnivorous or herbivorous, dwelled mostly on land, and varied from the size of a small dog to the largest land animals that ever lived. One group of dinosaurs evolved into birds. See more at ornithischian, saurischian. See Note at bird.