If you’ve used finger paint, you know the fun of making handprints. It seems ancient kids liked leaving their mark too! Scientists recently discovered 200,000-year-old fossils of kids’ handprints on a rock on the Tibetan Plateau in Asia.

The research team thinks the prints were made when kids pushed their hands into mud. Over centuries, the mud hardened and turned into limestone. Those handprints became fossilized.

The handprints may be some of the oldest examples of prehistoric art. Hands are important to humans, says Thomas Urban, an archaeologist who studied the fossils. “It’s not surprising that people like to leave their handprint.”