(CN) – Bony ray-finned fish with sharp teeth nibbled on other fish in the sea about 150 million years ago, according to researchers who say the newly discovered piranha-like creature presents the earliest evidence of fish feeding on other fish.
Sporting triangular teeth with serrated cutting edges on the inside of their lower jaws, these Jurassic-era fish were found in limestone deposits next to some of their victims – other fish with nibbled fins, according to researchers who published their findings in scientific journal Current Biology.
The piranha-like fish were discovered in modern-day southern Germany and unlike the modern piranha, these distant cousins swam in the ocean and grabbed their food on the go as they stealthily ate the fins of other fish.
"This is an amazing parallel with modern piranhas, which feed predominantly not on flesh but the fins of other fishes. It's a remarkably smart move as fins regrow, a neat renewable resource,” said study author David Bellwood from James Cook University in Australia. “Feed on a fish and it is dead; nibble its fins and you have food for the future."
The now extinct flesh-eating fish – named Piranhamesodon pinnatomus – swam in the ocean while small dinosaurs roamed the earth. Their fossils are now part of the natural history exhibit at Jura Museum in Eichstätt, Germany.
Researchers say the Jurassic fish exhibited convergent evolution with modern-day piranhas, which surprised the study’s authors.
Initially, they thought this slow-moving, but highly maneuverable fish was a scavenger, feeding on dead prey. But since they found it in shallow waters, it’s likely that the piranha-like fish exhibited mimicry similar to the modern piranha which swims among its prey.
Martina Kölbl-Ebert from the Jura Museum said the discovery of piranhamesodon pinnatomus was like “finding a sheep with a snarl like a wolf.”
“Fish as we know them, bony fishes, just did not bite flesh of other fishes at that time,” said Kölbl-Ebert. “Sharks have been able to bite out chunks of flesh but throughout history bony fishes have either fed on invertebrates or largely swallowed their prey whole. Biting chunks of flesh or fins was something that came much later.”
The piranha-like fish was discovered in the same limestone deposit as the Archaeopteryx, a fossil that is a link between dinosaurs and modern birds, which had both reptilian and avian features.
Funding for this research project was provided by the Volkswagen Foundation, the German Research Foundation, and the Australian Research Council.