Adamantisaurus (/ˌædəmæntᵻˈsɔːrəs/ AD-ə-man-ti-SAWR-əs) is a poorly-known genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. It is only known from six tail vertebrae but, as a sauropod, it can be assumed that this dinosaur was a very large animal with a long neck and tail.