Buried deep in the Canadian Arctic’s permafrost, a tiny fossil has shaken up what we thought we knew about ancient life. It’s just a rhinoceros tooth — but it’s been frozen there for around 24 million years, and inside it, scientists discovered something no one expected to last that long: perfectly preserved enamel protein, the natural material our bodies use to build the tough outer shell of teeth.
This finding matters because proteins last far longer than DNA. And in this case, they revealed the oldest detailed protein sequence ever recovered, which is a breakthrough that takes us deeper into the past than we’ve ever gone before.
The discovery comes from a team led by Ryan Sinclair Paterson at the University of Copenhagen’s Globe Institute, with collaborators from the University of York, the Smithsonian Institute, and Harvard University. Their findings, published in the journal Nature, didn’t just confirm the tooth’s age, they showed it belonged to a rhino from a branch that split off far earlier than scientists had thought, marking an ancient divergence between the Elasmotheriinae and Rhinocerotinae subfamilies.
Proteins: nature’s time capsules
DNA is fragile. It starts breaking down almost as soon as an organism dies. But enamel proteins? They’re like tiny biological safes, able to stay sealed and intact for millions of years, especially in the cold, dry stillness of the Canadian Arctic permafrost.
The team extracted and analyzed the enamel protein from the tooth and pieced together a genetic fingerprint far older than any DNA we’ve ever recovered. It’s the kind of leap forward that has paleoproteomics experts buzzing.
Even more exciting, this isn’t just about one rhino. The method could be used on other specimens, including fossils from Kenya from much warmer climates. If it works, it would break one of the biggest limits in ancient biology — that only cold-preserved remains can hold molecular secrets.
A global effort to rewrite the past
The University of Copenhagen’s Globe Institute brought its expertise in ancient biomolecules. The University of Cmabridge and Harvard University contributed evolutionary analysis. The Smithsonian Institute helped situate the find in a wider ecological story.
Together, they traced the tooth back to a time when the Arctic was home to strange and diverse rhino species. This specimen’s lineage diverged from others between 41 and 25 million years ago, proof that the divergence between the Elasmotheriinae and Rhinocerotinae subfamilies happened much earlier than expected.
And the beauty of this approach is that it doesn’t just identify a species. It opens a door to reconstructing diets, environments, even animal behavior from millions of years ago.
Rhino tooth is changing the story
For a long time, paleontology has pieced together the story of life on Earth using bones, fossils, and the occasionally, trace of ancient DNA. But now, thanks to paleoproteomics (the study of ancient proteins) scientists have a new way to dig even deeper into the past, with more detail and confidence than ever before.
If we can apply this to more fossils, then we could rewrite entire sections of evolutionary history. We could learn about animals that left no DNA behind, only teeth. About climates that shaped ancient life, and about how species adapted long before humans ever appeared.
The fact that this leap forward came from a single rhinoceros tooth is almost poetic. Something so small, tucked away in Arctic ice, has changed how we see the deep past.
And thanks to the collaboration between the different institutes around the world, we now know that enamel proteins can survive not just for centuries, but for tens of millions of years… carrying stories we’ve only just begun to tell.