Acrocanthosaurus (pronounce /ˌækrəˌkænθəˈsɔrəs/ or ak-ro-KAN-tho-SAWR-us; meaning 'high-spined lizard') is a genus of allosauroid theropod dinosaur that existed in what is now North America during the mid-Cretaceous Period, approximately 125 to 100 million years ago. Like most dinosaur genera, Acrocanthosaurus contains only a single species, A. atokensis. Its fossil remains are found mainly in the U.S. states of Oklahoma and Texas, although teeth attributed to Acrocanthosaurus have been found as far east as Maryland.