Why there are seashells on top of some mountains
Science biteThis morning, while we were hiking up the mountain, we spotted a tiny shell stuck in a rock, like finding a forgotten flip-flop in the middle of a meadow. And obviously we all looked at each other and went: “Wait, what is this doing up here, mate?”
The answer is as mind-blowing as it is real. Because where you’re huffing and puffing up the slope today, millions of years ago there were fish swimming around and little critters living their best life under the water.
So what exactly is a fossil?
A fossil is like a 3D snapshot nature took of a living thing from forever ago. Picture a shell sinking to the seafloor and getting covered by layer after layer of sand and mud. Over time, the original shell disappears, but it leaves a perfect mold behind. Then minerals from the ground fill that space until it turns into stone with the exact same shape. It’s like the sea packed a little cookie into a rock Tupperware for millions of years, just so you could stumble upon it today.

How did the ocean floor climb all the way up to the clouds?
To get it, think of Earth’s crust like a puzzle made of gigantic pieces that move with a patience that drives you mad. Sometimes two of those pieces crash into each other so hard that the ground has no choice but to crumple upward. It’s exactly what happens when you shove a rug against a wall: a bump forms and keeps rising into a little ridge. That “wrinkle” in the plates that make up Earth’s surface is what lifted ancient seabeds until they became mountain peaks thousands of meters high.
Is it easy to spot fossils in Spanish mountains?
In Spain we’re pretty lucky, we’ve got open-air geology museums all over the place. In the Pyrenees, the Baetic Systems, or the Cantabrian Mountains, it’s super common to be walking a trail and suddenly see sea snails or corals stamped right into the rock. It’s not that someone carried them up there to look cool, it’s the planet doing DIY on an epic scale. It’s proof that the landscape you see today hasn’t always looked like this, and that the Earth has way more memory than it seems.
Magikitos’ take: if today you feel out of place, remember the shell on the mountain. Maybe you’re not in the wrong spot. Maybe you’ve climbed far and high, but you still carry inside you all the strength of the sea from where you began.