*A newly discovered fossil of a piranha relative from 10 million years ago reveals the evolutionary history of the fish's iconic teeth.*

The find, described in a study published in the journal *Scientific Reports*, sheds light on how piranhas evolved their specialized dentition, which is used for biting and tearing flesh.

The fossil, named *Megapiranha paranensis*, is the largest known piranha relative ever found. It measured about 3 feet (1 meter) long and had teeth that were up to 1 inch (2.5 centimeters) long.

The researchers believe that *Megapiranha* is the ancestor of modern piranhas, which are found in South America's rivers and lakes. Piranhas are known for their sharp teeth and aggressive behavior, and they are often considered to be one of the most dangerous fish in the world.

The *Megapiranha* fossil was found in Argentina, in the same region where other piranha fossils have been found. The researchers believe that this area may have been a center for piranha evolution.

The study's findings provide new insights into the evolution of piranhas and their teeth. The researchers believe that the evolution of piranhas' specialized teeth was driven by the need to compete for food in the Amazon River basin.

The Amazon River basin is home to a wide variety of fish species, and piranhas must compete with other fish for food. The evolution of their specialized teeth allowed piranhas to become more efficient predators and to better compete for food.

The study's findings also provide new insights into the evolutionary history of piranhas. The researchers believe that piranhas may have evolved from a group of fish that lived in the ocean. These fish eventually moved into freshwater habitats, and they evolved into the piranhas that we know today.

The study's findings have important implications for understanding the evolution of piranhas and their teeth. The researchers believe that their findings could help to shed light on the evolution of other fish species that have specialized teeth.