Dilophosaurus (/daɪˌloʊfəˈsɔːrəs, -foʊ-/ dy-LOAF-o-SAWR-əs) is a genus of theropod dinosaur. It contains a single known species, Dilophosaurus wetherilli, known from fossil remains found in the Kayenta formation of Arizona. This rock formation has been dated to the early Jurassic Period (Sinemurian age), about 193 million years ago. Dilophosaurus was among the largest carnivores of its time (about 7 meters long) and had a pair of rounded crests on its skull.