Any species of four-legged, herbivorous, saurischian dinosaur in the suborder Sauropoda.
The sauropods include the largest of all dinosaurs and the largest land animals that ever lived. They existed from the Late Triassic Epoch into the Cretaceous Period (227–65 million years ago). All species had a small head, extremely long neck, massive body, thick, pillarlike legs, and a very long, tapering, whiplike tail. With their weak, sparse teeth, they cropped vegetation from even the tallest trees, apparently depending on swallowed stones or bacteria in the gut to digest plant matter. Species ranged from 50 ft (15 m) long to the 98-ft (30-m) Brachiosaurus , which weighed 80 metric tons. See also Diplodocus ; theropod .