The 2010 film "Mega Piranha" brought to life the piranha's prehistoric ancestor, which was several times bigger, and aptly named Megapiranha. The only remains of this ancient fish were first found in Argentina in the 1900’s, from which scientists deduced they existed during the Miocene period (5 to 23 million years ago), and had a biting force 30 times its own weight.
They weren't bigger than the average human, but ecosystems would be in peril had they existed today. While unconfirmed, it's believed that this prehistoric predator was a carnivore, given its teeth. Experts say the Megapiranha had enough biting force to crush shells of turtles and the tough armor of a certain species of catfish.
Add genetic experiments to the mix and you have cult favorite in the making. "Mega Piranha" featured these carnivores at insane sizes and with enough endurance to withstand everything from small-arms fire to a nuclear torpedo. To avoid spoilers, suffice it to say conquering these gargantuan fish will take more than anything man’s arsenal could produce.
The normal piranha today may hurt you, but it could be worse. Their sinister nature has become the stuff of legend, immortalized in such all-time favorite flicks like Piranha 3D.