It’s a strategy still used today. Working together, lions will take on prey as big as a four-ton elephant, and they only have teeth and claws. Deinonychus employs an array of weaponry more powerful than any creature today. Sauroposeidon’s only defense is its massive size, but Deinonychus have learned that nearly any defense can be breached with the right armaments, like recurved hand claws almost 8 centimeters long designed to grip into the bodies of prey like a mountain climber’s spikes.

 

The ideal attack is to jump up, grab ahold of the prey, position the prey, and then strike. So the arms are to position your body to deliver that killing blow. 

 

It could strike very quickly, and it could, if it was attacking a larger animal, use those arms to pull itself up against it. By doing so, it could bring its other main weapon into attack, and that’s its foot claws. 

 

The name Deinonychus means “terrible claw”. It’s a reference to the hinged bone on its foot. The cutting edge is sheathed in keratin, the same substance that forms a cat’s claw. But on a Deinonychus, this claw is 10 centimeters long. This lethal weapon is sharpened to a point and can flex almost 180 degrees. To keep the knife razor-sharp, Deinonychus holds it up off the ground until the moment it’s needed. Then, in one lightning-fast swipe, this sickle can rip deep into flesh, delivering a kicking blow with 200 kilos of cutting force. 

 

The key to the Deinonychus’ killing blow is the hind leg. The hind leg is the strongest organ in the body by far and ends in a huge claw like a box-cutting knife. So that cutting, curved knife into your belly, into the target would cause a fatal wound.