Deinonychus antirrhopus was a small, bipedal, carnivorous dinosaur. It is generally believed among evolutionists to have existed about 65-70 million years ago during the Cretaceous period, but young earth creationists accept it as having been created on the sixth day, along with all the other dinosaurs. It had a long, sickle-like claw on the end of its big toe. Deinonychus fossils were first discovered in 1931 by Barnum Brown in southern Montana. In 1964 the fossils were designated Deinonychus antirrhopus by John Ostrom and Grant Meyer.
Deinonychus are believed by many scientists to have been feathered, citing other feathered dinosaurs such as microraptor and especially its close relative Velociraptor mongoliensis, fossils of which have quill knobs for the attachment of feathers on the forelimb bones. .