Deinonychus is a genus of dromaeosaurid theropod dinosaur with one described species, Deinonychus antirrhopus. This species, which could grow up to 3.4 meters (11 ft) long, lived during the early Cretaceous Period, about 115–108 million years ago (from the mid-Aptian to early Albian stages). The seventh supersaur in the superlative series may only have been three and a half meters in length, but it was one of the most dangerous and intelligent dinosaurs to have ever walked the earth.