After being a mystery for many years, scientists now reveal that a 280-million-year-old fossil has been partly forged. The fossil, named Tridentinosaurus antiquus, was discovered in the Italian alps in 1931 and was initially thought to be a crucial find for understanding early reptile evolution.
However, new research by Dr Valentina Rossi of University College Cork, Ireland, has revealed that the fossil is mostly just a carved lizard-shaped rock surface painted black. This has led the team to urge caution in how the fossil is used in future research.
The body outline of the fossil, which initially appeared dark against the surrounding rock, was believed to be preserved soft tissues, leading to its classification as a member of the reptile group Protorosauria. The remarkable preservation of the fossil had left many experts uncertain about what group of reptiles this strange lizard-like animal belonged to and more generally its geological history.
The fossilised skin had been included in articles and books but never studied in detail until now. Dr Rossi, of UCC’s School of Biological, Earth and Environmental Sciences, said that fossil soft tissues are rare but can reveal important biological information, such as the external colouration, internal anatomy and physiology, when found in a fossil.
The microscopic analysis showed that the texture and composition of the material did not match that of genuine fossilised soft tissues. Preliminary investigation using UV photography revealed that the entirety of the specimen was treated with some sort of coating material. Coating fossils with varnishes and/or lacquers was the norm in the past and sometimes is still necessary to preserve a fossil specimen in museum cabinets and exhibits. The team was hoping that beneath the coating layer, the original soft tissues were still in good condition to extract meaningful palaeobiological information.
The findings indicate that the body outline of Tridentinosaurus antiquus was artificially created, likely to enhance the appearance of the fossil. This deception misled previous researchers, and now caution is being urged when using this specimen in future studies.
Co-author Prof Evelyn Kustatscher, coordinator of the project “Living with the supervolcano”, funded by the Autonomous Province of Bolzano said that the peculiar preservation of Tridentinosaurus had puzzled experts for decades but now, everything makes sense. What was described as carbonized skin is just paint.
However, all the fossils are not a complete fake. The bones of the hindlimbs, in particular, the femurs seem genuine, although poorly preserved. Moreover, the new analyses have shown the presence of tiny bony scales called osteoderms – like the scales of crocodiles – on what perhaps was the back of the animal.
This study is an example of how modern analytical palaeontology and rigorous scientific methods can resolve an almost century-old palaeontological enigma.