Ten Million Years Ago, This Giant Piranha Had a Bite Stronger Than a Great White Shark

In 2009, scientists turned their attention to the fossilized remains of a formidable prehistoric creature: the megapiranha that swam in the warm waters of South America around 8 to 10 million years ago.

Megapiranha paranensis

Unearthed from the Argentine Paraná geological formation at the dawn of the 20th century, this fossil of Megapiranha paranensis was identified in the 1980s as a fragment of an upper jaw. Featuring three large, pointed teeth, the specimen underwent a detailed study a few decades later. Paleontologist Alberto Cione and his colleagues noted at the time a zigzag arrangement, appearing halfway between the dentition of contemporary piranhas and that of related species with a markedly different diet.

“We observe only one row of teeth in piranhas, compared with two in pacus, which are essentially herbivores,” explained the authors of the study, published in the Journal of Vertebrate Paleontology.

Because there are so few specimens of M. paranensis, its measurements remain debated. The 2009 study concluded the creature could measure more than a meter in length and weigh about a human, while later work estimated its length at around 70 centimeters and its weight at about ten kilograms.

Nevertheless, there is no doubt that this giant piranha possessed a formidable bite. Biomechanical simulations estimated a bite force ranging from 1,240 to 4,749 newtons for M. paranensis, sufficient to break bones. In the highest estimate, for a 73-kilogram specimen, the bite force would have exceeded that of a three-tonne great white shark.

Powerful Jaws

Today, piranhas still stand out for their fearsome bite. Living mainly in the basins of the Amazon and Orinoco and weighing just over a kilogram, Serrasalmus rhombeus exhibits a bite force of 320 newtons, the strongest ever measured in a modern bony fish.

This feat is closely linked to its powerful chewing muscles, which account for more than 2% of its body weight.

Between 2 and 4 million years ago, South America also housed the largest rodent known to science, whose bite would have been sufficient to break a human femur.