Dreadnoughtus is a genus of titanosaurian sauropod dinosaur containing a single species, Dreadnoughtus schrani. It is known from two partial skeletons discovered in Upper Cretaceous rocks of the Cerro Fortaleza Formation in Santa Cruz Province, Argentina. It is one of the largest terrestrial vertebrates known from reasonably complete remains, with the immature type specimen measuring 26 metres (85 ft) in total body length and weighing up to 48–49 metric tons.