If you’re old enough to remember the iconic 80s arcade game Galaga, you’ll take one look at the teeth of the Galagadon, a genus of extinct sharks, and know exactly how it got its name. When examined side by side, its teeth look a lot like the spaceships in this retro video game.

This species of small carpet shark once called the rivers and wetlands of South Dakota home, some 67 million years ago during the Late Cretaceous period. We know this solely because of the analysis that palaeontologists carried out on the teeth, which are the only trace of the Galagadon’s existence.

What’s crazy is that the teeth are only the size of a grain of sand. Without a microscope, you’d never know they were teeth at all.

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