Toothy, ancient fi sh likely nibbled on other fi sh
Some 150 million years ago, prehistoric fish swimming in the sponge and coral reefs of what is now southern Germany might not have suspected there was a piranhalike predator prowling among them. But by the time they realized the danger — Chomp! — the sneaky creature would have bitten off one of their fins.
Back then, these waters were teeming with bony fish called pycnodontiformes, which were known for their crushing teeth likely used for smashing snail shells and sea-urchin spines. Scientists thought, for the most part, that other fish were not on their menu.
But now, researchers have found a pycnodontiform with razor-sharp teeth that they think ripped chunks of flesh, especially fins, from other fish. They named it Piranhamesodon pinnatomus. The finding, published Thursday in the journal Current Biology, represents the earliest record of flesh-eating in bony fish and may cause scientists to rethink the predatory practices of this group.
“It’s a wolf in sheep’s skin,” said Martina Kölbl-Ebert, a vertebrate paleontologist and director of the Jura-Museum Eichstätt in Germany. “This one had daggers and scissors in the mouth, implying a completely different mode of feeding.”
With scalpels, fine-needles and a microscope, KölblEbert and her colleagues examined the fossil in 2016. It came from the same fossil deposit where scientists discovered Archaeopteryx, the famous feathered dinosaur.
This area was most likely a shallow tropical sea dotted with small islands inhabited by insects, lizards and dinosaurs when This fossil found by researchers in Germany shows a prehistoric fish with sharp teeth that allowed it to eat prey much larger than itself.
the piranhalike fish was alive, according to KölblEbert. After extracting the fossil from the rocks, they performed a micro-CT scan on the specimen.
Although the Piranhamesodon pinnatomus may have looked like other colorful coral fish from the outside, there were major differences inside its mouth.
Most pycnodonts had front teeth shaped like chisels that they used for grasping, as well as flat, cobble-shaped teeth for crushing. But the newly discovered species, just a few inches in length, had six
long, pointed knifelike teeth that were slightly curved backward as well as six triangular teeth with serrated edges.
“We were stunned that this fish had piranhalike teeth,” Kölbl-Ebert said.
While its pycnodont relatives mostly swallowed their prey whole, the sharp teeth of the newly discovered fish would have allowed it to munch on prey that was much larger than itself. According to the researchers, prehistoric sharks and sea turtles were the only other known flesh-eaters in those waters, known as
the Solnhofen Archipelago, during the period known as the Late Jurassic. That made Piranhamesodon pinnatomus a pioneer among bony fish when it came to slicing up prey.
Fossils of fish with missing or bitten fins suggest Piranhamesodon pinnatomus nipped at the appendages of unwary fish while they were still alive, a practice seen in modern piranhas.
“If you bite a fish in the belly it might die and then it’s lost,” Kölbl-Ebert said, “but if you just nibble bits from the fin it will regrow and you can do it all over again.”