Dinosaurs are an extinct group of reptiles that lived during the Mesozoic Era, specifically during the Triassic, Jurassic and Cretaceous Periods. Dinosaurs were exclusively land‐dwelling vertebrates whose hind limbs were held erect and under the body. They ranged from bipeds to quadrupeds with a wide variety of sizes. Explore the diversity of dinosaurs, from their size to their appearance, using Wolfram|Alpha.
Reference dinosaurs by scientific name, usually by genus or species, or search by higher order taxa.