The 'swift-seizer' Velociraptor is known as a fast and ruthless hunter of the late Cretaceous. Much smaller than its contemporary Tyrannosaurus Rex, the Velociraptor measured about 1.5 metres in height, and is believed to have been covered in down and feathers, to maintain body heat and aid in movement.  It also possessed a large sickle-shaped claw on its hind feet - like a modern cassowary -  likely used to disembowel or detain prey.