Saber-Toothed Anchovies Swam in the Oceans Millions of Years Ago

The anchovies we eat today are small, plankton-munching fish that show up in our salads and on pizzas. But as new research suggests, anchovies’ ancient predecessors had more of a bite.

A team of scientists analyzed the remains of two now-extinct cousins of anchovies: a 30-centimeter-long fossil embedded in rock in Chièvres, Belgium, and a partial fossil discovered in the Punjab province of Pakistan, both dated to about 45 million to 50 million years ago. The two fish sported a row of fanged teeth on the bottom and, most remarkably, a lone “saber” tooth on top, Laura Geggel reports for Live Science.

Even weirder: the singular tooth is just slightly off-center, the authors describe in their study published in Royal Society Open Science.

This striking set of teeth might indicate that these ancient anchovies were predators that ate other fish. But the teeth are so unusual—especially that top pincer—that the team doesn’t know for certain what they were used for, reports Hannah Osborne for Newsweek.

“They are clearly the teeth of a predator,” Alessio Capobianco, co-author on the study from the University of Michigan, tells Newsweek. “Living species with large fangs use them in different ways: some of them use the fangs to stab or impale their prey, some use them to make their mouth a sort of ‘cage’ or ‘trap’ for smaller fishes. For the saber-toothed anchovies, this is purely the realm of speculation for now, as there are no good modern analogues with a comparable set of teeth.”

Researchers named the new species from Pakistan the Monosmilus chureloides, a reference to the churel, a shapeshifting creature with fangs that features in some South Asian legends, reports Rodrigo Pérez Ortega for Science. That species could grow up to 3.2 feet in length and had a front tooth that was about one inch long, per Newsweek. It lived in shallow seas in modern-day Pakistan, about 45 million years ago, per LiveScience.

The fish from Belgium lived about 50 million years ago, during the early Eocene epoch, reports Alexandra Garrett at CNET.

Both anchovy-adjacent species likely evolved after the Cretaceous-Palaeogene extinction event that ended the reign of dinosaurs on our planet. Some scientists hypothesize that, after dinosaurs went extinct and left ecosystems without predators, some species of fish might have evolved new adaptations to become better predators themselves, per CNET.

“The discovery of saber-toothed anchovies shows us that, alongside these successful evolutionary stories that persist to the modern day, other lineages also evolved remarkable specializations to occupy the ecological role of predators, but they were ultimately unsuccessful,” Capobianco tells Newsweek. “Viewed in this context, organisms like the saber-toothed anchovies can be called ‘failed evolutionary experiments’—short-lived groups that did not survive to the modern day with remarkable ecologies that cannot be predicted on the basis of living species.”

Nora McGreevy | | READ MORE

Nora McGreevy is a former daily correspondent for Smithsonian. She is also a freelance journalist based in Chicago whose work has appeared in Wired, Washingtonian, the Boston Globe, South Bend Tribune, the New York Times and more.