The word dinosaur was coined by Richard Owen in 1841, deinos (terrible) + sauros (lizard) which describe 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. Ceratosaurus ("horned lizard"), was a large predatory theropod dinosaur. A carnivorous American Jurassic dinosaur allied to the European Megalosaurus. The animal was nearly twenty feet in length, and the skull bears a bony horn core on the united nasal bones. Shown here is Ceratosaurus nasicornis skeleton restoration by O.C. Marsh from 1896, depicted in an erroneous upright position.