Futabasaurus (meaning "Futaba lizard") is an informal name for a genus of possible tyrannosaurid theropod dinosaur from the Late Cretaceous Futaba Group of the Ashizawa Formation of Japan. It is currently only known from a single fossilized shin bone. The name is an English conversion of the Japanese nickname for the specimen. "Futaba-ryu," meaning "Futaba dragon." If the specimen is eventually described and named, it will require a different name, as the name Futabasaurus has been used for a genus of plesiosaur since the theropod's informal name's first mention.
Futabasaurus was featured in the Jurassic Park Institute now available to browse on Dinopedia.