A new scientific mystery has emerged from one of the world’s driest regions. Deep within ancient desert rocks, researchers have found tiny, tunnel-like formations that appear to have been carved by an unknown lifeform—one that has no modern equivalent, may be extinct, and could have played a previously overlooked role in shaping Earth’s carbon cycle.
The structures were discovered in limestone and marble from deserts in Namibia, Saudi Arabia, and Oman. They are less than a millimeter wide but can stretch up to three centimeters long, resembling perfectly formed micro-burrows. Scientists are confident these formations weren’t created by geological processes. Instead, the evidence points toward a biological origin—one rooted in deep time and surrounded by unanswered questions.
The strange phenomenon was first observed 15 years ago by Professor Cees Passchier from Johannes Gutenberg University Mainz during geological fieldwork in southern Africa. At the time, the structures seemed unusual but unremarkable. However, after later finding identical formations in rock samples from other arid regions and conducting detailed analyses, Passchier and his team came to a startling conclusion: these tunnels were likely formed by an ancient microorganism, one capable of surviving inside rock itself.
“We were surprised because these tubes are clearly not the result of a geological process,” Passchier said in a statement.
Further testing revealed powdery calcium carbonate inside the tunnels—the same compound that makes up marble. This suggests the organism that created the tunnels may have burrowed into the rock to access nutrients locked inside the mineral structure, leaving behind powdered residue as it moved.
Such organisms, known as endoliths (from the Greek for “inside rock”), are known to survive in extreme environments. Blue-green algae have been found living just beneath rock surfaces in Antarctica and the scorching deserts of Israel and California. But none of the known endoliths match the behavior or physical traces left by the lifeform responsible for these tunnels.
Ongoing Mystery
Even more puzzling, the team was unable to extract any DNA or protein from the samples. The structures are simply too old—potentially up to 2 million years—which means there may be no genetic evidence left to study.
“We don’t currently know whether this is a life form that has become extinct or is still alive somewhere,” said Passchier. “What is so exciting about our discovery is that we do not know which endolithic microorganism this is. Is it a known form of life or a completely unknown organism?”
The implications of this discovery reach well beyond desert geology. If such lifeforms contributed to the long-term breakdown of carbonate rocks, they may have played an unseen role in Earth’s carbon cycle—a system that regulates how carbon is stored and released in the planet’s atmosphere. These micro-scale biological processes could have influenced climate patterns, chemical balances, and even the habitability of ancient ecosystems.
“This form of life, of which we do not know whether it still exists, could be important for the global carbon cycle,” Passchier added. “It is therefore essential that the scientific community becomes aware of it.”
There’s also a deeper question at play: if Earth once hosted organisms capable of thriving inside rock by extracting minerals as food, could similar life exist elsewhere? The survival strategy observed in these mysterious tunnels could mirror how life might endure on Mars, or deep beneath the surfaces of icy moons like Europa and Enceladus. If life can adapt to such extremes here, it’s not unreasonable to think it might do so elsewhere.
Although no definitive answers have emerged, the discovery opens new avenues for planetary science, microbiology, and climate research. The study has been published in the Geomicrobiology Journal, and scientists are now urging further investigation into similar rock formations around the world.
This unknown lifeform—once invisible, buried in stone—has suddenly stepped into the scientific spotlight. It may have vanished millions of years ago, or it might still be thriving somewhere in the shadows. Either way, it’s forcing us to rethink the quiet forces that shape our planet—and perhaps others. This is why I love science!
