Scientists have discovered mysterious microscopic tunnels in marble and limestone formations across Namibia, Oman, and Saudi Arabia. These structures, which are embedded in rock, may be remnants of an unknown life form.
Geologist and Johannes Gutenberg University Mainz (JGU) Professor Cees Passchier first identified the formations during fieldwork in Namibia. The structures appear as tiny tubes, about half a millimeter wide and up to three centimeters long, arranged in parallel bands stretching across rocks for up to ten meters.
Their consistent pattern and the presence of biological material suggest they are not the result of natural fractures or erosion but rather a sign of past biological activity.
Further investigations revealed similar structures in Oman’s limestone and Saudi Arabia’s marble, indicating the phenomenon was not limited to one location. Scientists believe these formations may have developed under a different climate, possibly when the region was more humid than it is today.
Experts suspect that microorganisms may have carved these tunnels by feeding on calcium carbonate in the rocks. A fine dust residue composed of the same mineral was detected, reinforcing the idea that these organisms extracted nutrients from the stone.
“We were surprised,” Passchier said. “These tubes are apparently not the result of a geological process.”
Some bacteria and fungi can survive in extreme environments by using minerals for energy. However, scientists have not yet been able to extract DNA or proteins from the samples, so it cannot be confirmed yet if these microorganisms are extinct or still present somewhere on Earth.
Researchers believe these microorganisms may have shaped the global carbon cycle. If they contributed to the breakdown of calcium carbonate, they might have influenced the levels of carbon dioxide (CO₂) in Earth’s atmosphere.
Passchier explained that microbial activity in rocks can significantly impact the composition of the environment over long periods. If these organisms were widespread, they could have helped regulate CO₂ levels in various ways.
The discovery has sparked interest among scientists studying endolithic microorganisms, unknown life forms inside rocks. These organisms are known to thrive in extreme conditions, such as deserts and deep-sea environments, making them potential candidates for surviving in other planets’ harsh landscapes.
The findings raise several key questions: Did an undiscovered species create these tunnels? Could similar life forms still exist in hidden parts of the world?
Researchers hope further studies in microbiology and geosciences will provide answers. For now, the identity of the organism remains unknown.
But solving this mystery could reshape the understanding of life’s boundaries not just on Earth, but also in the search for life beyond our planet.
