Length: 10-13 ft. Weight: 110-165 lbs. Period: Early Cretaceous

Over 100 million years ago, a killing machine roamed the earth.  Fierce and fearless, packs of Deinonychus stalked their victims, bringing instant death with the slash of their terrible claws.

Built for Power and Speed 
The Terrible Claw 
A Smart Dinosaur 
How Do We Know That? 
Mesozoic Timeline 

Deinonychus was one of the most lethal predators of the early Cretaceous period, a dinosaur that spent most of its time hunting. 

Built for Power and Speed   
Deinonychus was a small bipedal dinosaur.  Its body was 10-13 feet (2.5-4 meters) long and it weighed only about 175 pounds (8 kilograms).  Deinonychus walked on two bird-like legs.  Compared to other theropods its size, Deinonychus' legs were shorter and bulkier.  Although Deinonychus would have been able to run faster than a human would, scientists think its body was designed more for power than speed.  This would have helped Deinonychus ambush its prey.

Deinonychus had a long tail with bony rods running along the spine to make it very rigid.  The dinosaur used this stiff tail while running, for balance and for making sharp turns.
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The Terrible Claw   
Deinonychus’ name means “terrible claw.”  This dinosaur was equipped with sharp, curved claws on the three-fingered hands of each short arm.  Deinonychus is most famous for the fearsome claws on its four-toed feet.  The second toe of each foot featured a vicious, sickle-shaped claw 5 inches (13 centimeters) long.  This razor-sharp claw could swivel up out of the way when Deinonychus was running. 

When attacking its prey, Deinonychus could leap into the air and kick out at a victim with its clawed feet.  It could fight while balanced on one leg, using the other to slash at a victim.  Deinonychus took down its prey by simultaneously biting at the victim’s head and tearing at its stomach with the deadly sickle-clawed feet.
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A Smart Dinosaur   
Deinonychus belonged to the dromaeosaurids, thought to be one of the smartest  dinosaur families.  It had a fairly large brain, and the sensory abilities to see, smell and chase fast-running animals.
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How Do We Know That?   
A recent fossil find in Montana, USA, revealed five Deinonychus skeletons grouped with the remains of a Tenontosaurus, a two-footed herbivore.  Scientists view this as evidence that Deinonychus sometimes hunted in packs.
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Mesozoic Timeline

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