- Acrocanthosaurus (/ˌækroʊˌkænθəˈsɔːrəs/ AK-roh-KAN-thə-SOR-əs; lit. ‘high-spined lizard’) is a genus of carcharodontosaurid dinosaurs that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous, from 113 to 110 million years ago. Like most dinosaur genera, Acrocanthosaurus contains only a single species, A. atokensis. It had a continent-wide range, with fossil remains known from the U.S. states of Oklahoma, Texas, and Wyoming in the west and Maryland in the east. However, most of these remains are assigned to the species based on the assumption that Acrocanthosaurus is the only large carcharodontosaurid from North America during this time, and the possibility exists that some referred specimens could represent distinct taxa.