Megapiranha is an extinct genus of serrasalmid characin fish that lived 8 to 10 million years ago, in the Late Miocene. It’s estimated to have reached lengths of up to 1.3 meters, which is about four times the size of piranha alive today. These estimates are based upon fossil specimens that have been discovered.
Based on field studies carried out on the black piranha (Serrasalmus rhombeus), the largest living species in the carnivorous clan, Megapiranha may have had a stronger bite than alligators, sharks and even Tyrannosaurus rex. The largest of the 15 fish tested weighed 1.1 kg and measured 37 cm in length. It could clamp down on researchers’ equipment with a force of 30 times its own weight, a ratio which is unmatched among vertebrates. The scientists published their findings in the journal Scientific Reports¹.
Megapiranha paranensis, which could have reached lengths of up to 1.3 meters and weighed up to 73 kilograms, could have had a jaw tip bite force as high as 484 kilograms. Previous studies had shown that T. rex‘s bite force was about three times that of M. paranensis. However, T. rex is more than 100 times heavier than M. paranensis. Scaling down to size, M. paranensis has a stronger bite. They also had teeth fringed with tiny serrations, with stout circular rout, allowing them to slice through flesh, crush the shells of turtles, and pierce the armor plates of catfish that lived in the same ecosystem.
Reference: “Mega-Bites: Extreme jaw forces of living and extinct piranhas (Serrasalmidae)” by Justin R. Grubich, Steve Huskey, Stephanie Crofts, Guillermo Orti and Jorge Porto, 20 December 2012, Scientific Reports.