Megapiranha

Megapiranha paranensis is an extinct serrasalmid characin fish from the Late Miocene (8–10 million years ago) of Argentina, described in 2009. It is thought to have been about 71–128 centimetres (2.33–4.20 ft) in length. The holotype consists only of premaxillae and a zigzag tooth row; the rest of its body is unknown. This dentition is reminiscent of both the double-row seen in pacus, and the single row seen in the teeth of modern piranhas, suggesting that M. paranensis is a transitional form. Its bite force is estimated between 1,240–4,749 N (279–1,068 lb_f).