A 280-million-year-old fossil that has puzzled researchers for decades has been shown, in part, to be a forgery after a new examination of the remains.

The discovery led the team, led by Dr Valentina Rossi of University College Cork, Ireland (UCC), to urge caution in how the fossil is used in future research.

Tridentinosaurs Archaic It was discovered in the Italian Alps in 1931 and is considered an important specimen for understanding the evolution of early reptiles.

The outline of its body, appearing black against the surrounding rock, was initially interpreted as preserved soft tissue. This led to its classification as a member of the reptile group Protorosauria.

However, this new research has been published in a scientific journal. Palaeontologyshows that the fossil, famous for its remarkable preservation, is mostly just black paint on the surface of a carved lizard-shaped rock.

The supposed fossilized skin was celebrated in articles and books but never studied in detail. The fossil’s somewhat odd preservation has left many experts uncertain about the group of reptiles this strange lizard-like creature belongs to and its geological history in general.

Dr Rossi, from UCC’s School of Biological, Earth and Environmental Sciences, said:

“Fossil soft tissues are rare, but when found in a fossil they can reveal important biological information, for example, external coloration, internal anatomy and physiology.

“With all our questions answered, we had to study this fossil specimen in detail to uncover its secrets — even those we might not have wanted to know.”

Microscopic analysis showed that the texture and structure of the material did not match the soft tissue of real fossils.

Preliminary investigation using UV photography revealed that the entire sample was treated with some kind of coating material. Coating fossils with varnish and/or lacquers was common in the past and is sometimes still necessary to preserve fossil specimens in museum cabinets and displays. The team was hoping that beneath the coating layer, the original soft tissue was still in good condition to extract meaningful paleogeological information.

The results show that the body diagram Tridentinosaurs Archaic was artificially created, possibly to enhance the fossil’s appearance. This illusion misled previous researchers, and caution is now being urged when using this sample in future studies.

The team behind the research includes Italy-based University of Padua, the Museum of Nature South Tyrol, and the Museo delle Sciences in Trento.

Professor Evelyn Costascher, coordinator of the “Living with Supervolcano” project, funded by the Autonomous Province of Bolzano, said:

“Specific protection of Tridentinosaurus had been puzzling experts for decades. Now, it all makes sense. What was described as carbonized skin is just paint.”

All is not lost, however, and the fossil is not a complete fake. The bones of the hind limbs, especially the femur, appear to be genuine, although poorly preserved. Additionally, new analyzes have revealed the presence of small bony scales called osteoderms — similar to crocodile scales — that may have been the animal’s back.

This study is an example of how modern analytical paleontology and rigorous scientific methods can solve a nearly century-old palaeontological mystery.