The Mind-Blowing Mystery of Fossilized Skin: How a Prehistoric Fish Kept Its Scales Perfect for 52 Million Years!
A fossil that defies the rules of time
For decades, paleontologists assumed that only oxygen-free environments could preserve soft tissues, as oxygen accelerates decomposition. However, a fossil of Diplomystus dentatus has just challenged that dogma.
This specimen—exceptionally preserved for 52 million years—retains intact skin and scales, something nearly impossible in the fossil record. The study, led by the University of Curtin (Australia), explains for the first time how a natural chemical process, born from the fish’s own fat decomposition, created the necessary conditions for its fossilization.
The secret was in the fat
Dr. Amy Elson, from the Curtin Faculty of Earth and Planetary Sciences, explained that the discovery changes the understanding of biological preservation:
“We generally think that oxygen-free conditions are essential for preserving soft tissues. But we discovered that, even in oxygen-rich environments, chemical reactions can protect them for millions of years.”
The process began when the fish’s skin started to degrade. This modified the sediment’s local chemistry, blocking the formation of carbonates (which accelerate decomposition) and promoting the precipitation of phosphates, acting as a protective layer.
A microenvironment rich in oxygen… and paradoxes
This fossil formed in an environment that, unlike other exceptionally preserved deposits, was not anoxic. Geochemical analysis showed elevated levels of oxidation in the skin, indicating that initial decomposition was crucial: that local chemical process “sealed” the tissues before oxygen could destroy them.
Researchers describe it as a paradox: the fish’s death generated its own chemical defense mechanism against the passage of time.
From paleontology to biotechnology
Professor Kliti Grice, director of the Western Australia Organic Geochemistry and Isotopes Center, highlighted that the discovery not only explains a fossil phenomenon but can also inspire:
“Understanding how certain biological materials persist for millions of years can help design methods to preserve tissues in medicine, improve carbon storage, or even optimize mineral exploration.”
This discovery demonstrates that Earth’s history is not only written in bones, but also in the invisible processes that surrounded them.
Source: [link to the original article]
