Deinonychus is a genus of carnivorous Dromaeosaurids that lived in the Cretaceous period 115–108 million years ago. Only species that has been described is D. antirrhopus.
Deinonychus most probably had feathers as many other Dromaeosarids; geologically older microraptor and very closely related, geologically younger Velociraptor mongoliensis -- are known to have had feathers. Even its anatomy was extremely birdlike and there has even been speculation that Dromaeosaurids evolved from tree-dwelling, small dinosaurs -- a group that also branched to become birds.
It grew to around 3.4 metres (11 ft. 2 in.) long, and would weigh around 73 kilograms.