"Arkansaurus fridayi" is the informal name of a dinosaur that was discovered in Lockesburg, Arkansas. "Arkansaurus fridayi" was a bipedal coelurosaurian dinosaur, a group of theropods that includes the Tyrannosauridae, Ornithomimidae, and Maniraptora. Its nearest relative was thought to be Ornithomimus, a bird or ostrich-like dinosaur. It is named for the state and its discoverer J.B. Friday, who found the dinosaur's fossilized foot on his farm in 1972. They are the only dinosaur fossil remains ever found in Arkansas.