Brachylophosaurus (/brəˌkɪləfoʊˈsɔːrəs/ brə-KIL-ə-fo-SAWR-əs or /ˌbrækiˌloʊfəˈsɔːrəs/ brak-i-LOH-fə-SAWR-əs; meaning "short-crested lizard", Greek brachys = short + lophos = crest + sauros = lizard, referring to its small crest) was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from several skeletons and bonebed material from the Judith River Formation of Montana and the Oldman Formation of Alberta, living about 78 million years ago.