Deinonychus

Deinonychus was the first of the raptors (technically called "Dromaeosaurs") to be known from a nearly complete skeleton. Velociraptor had been discovered forty years earlier but was known only from a skull and a few bones of its hands and feet.[1]

The skeleton of Deinonychus were first to show the now infamous sickle-shaped retractable foot claw (8 inch), used for ripping open the skin of a victim, causing the preys guts be ripped and with a considerable amount of damage. Deinonychus also had a nasty bite, with over 60 knife-like teeth. Although with a deadly bite its arms and legs would be most powerful and could rear on one leg and kick an opponent.[1]

Dr. John Ostrom discovered Deinonychus in 1964. Dr. Ostrom believed that this dinosaur was an agile, swift predator, more like a warm-blooded mammal or bird than a cold-blooded crocodile.