A modern-day megamouth (Photo: FLMNH Ichthyology/Wikimedia)

100 million years ago, a prehistoric shark swam the shallow waters around what’s now Russia. A group of scientists found a collection of this shark’s fossilized teeth, and they determined that it had one key characteristic—a terrifyingly large mouth, similar to the giant rift in the face of today’s very rare megamouth shark.

In fact, it’s so similar that the new shark is called Pseudomegachasma, after the current day megamouth, reports Discovery News. 

This is the kind of mouth that makes one glad that the corresponding shark is long extinct. But this shark was a relatively gentle predator. It only ate plankton.

Sharks have a reputation as cold-blooded meat eaters, but there are a few kinds, even today, that prefer plankton. The modern megamouth is one of them, actually. The basking shark and the whale shark also gorge themselves on tiny, tiny creatures. This extinct shark appears to have evolved independently of today’s sharks, though. Apparently a giant shark mouth is just so advantageous that evolution has invented it more than once. 

Bonus find: A strawberry that wants to be a bear

Every day, we highlight one newly lost or found object, curiosity or wonder. Discover something unusual or amazing? Tell us about it! Send your finds to sarah.laskow@atlasobscura.com.