It can be hard to imagine a world that looks drastically different than the one we live in today, even if we know that’s how it was.

Like imagining robust, green, fruiting trees thriving in the Arctic – it just doesn’t compute!

You can’t argue with fossils, though.

At least, you shouldn’t.

There are stumps of old trees far above the Arctic Circle that are large enough to be spotted from the air – on an island where, now, nothing much grows at all.

45 million years ago, though, the Arctic was much warmer and more habitable, which is how what turned out to be walnut trees were able to thrive for so long.

The island where the tree stumps remain is called Axel Heiberg, the seventh-largest island off the coast of Canada. It’s further north than most of Greenland and is so cold the Inuit had already moved on by the time Europeans arrived.

Astronauts simulating life on Mars sometimes visit today, but other than that, scientists are the only people who brave the climate in pursuit of knowledge.

Professor James Basinger, an author on this study, issued a statement about what they found there.

“When you walk into the site, the first thing you notice are these big stumps, a meter or more in diameter, and they’re still rooted in the soil that they grew in. It’s completely out of place. The closest living trees are 1,864 miles away.”

The fossilized stumps lived during the Eocene epoch, where average temperatures in the area were likely 50°F. That said, the winters were as dark as they are today, so researchers are keen to learn how forests thrived in warmer – but darker – climates than they normally prefer.

These are the forests that would have hosted dinosaurs, as well, says Dr. Steven Manchester of the Florida Museum of Natural History.

“There aren’t really that many places around where you can go to see fossils that are preserved that well.”

The trees and their nuts on the island were mummified when the forest was buried beneath a swamp. This kept bacteria and fungi from decomposing the remains.

The trees are not a known species, but are walnut trees. They were joined by hickory and pine trees, along others, which grew to around 130 feet.

The researchers performed CT scans on the nuts, which led to the classification of three new species of the tree, named Juglans eoeoarctica, J. nathorstii and J. cordata.

It really is wild to think about, isn’t it?

The future might not look at all like we expect.

If you thought that was interesting, you might like to read about the mysterious “pyramids” discovered in Antarctica. What are they?