There’s a terrible B-movie from 2010 called Megapiranha, about giant, genetically modified piranhas that wreak havoc upon Floridian tourists. One of them leaps out of the water and bites a helicopter. It’s all rather silly, but if you look on Wikipedia’s entry for the film, you’ll see these words at the top: “For the prehistoric creature, see Megapiranha.”

Yes, Megapiranha existed. At around 71 centimetres long, it wasn’t big enough to attack a chopper, but it was still three times the size of its modern meat-eating cousins.

Now Justin Grubich from American University in Cairo has found that Megapiranha and its modern relatives have some of the strongest bites of any fish, relative to their size. Pound