The oldest fossil reptile in Italy?It was a deception, in reality it was a lacquered artefact

The Tridentinosaurus has always been considered the oldest fossil reptile in Italy, but it was not:it was believed to have preserved its black skin, and for this reason it was considered unique.But in reality it was just a lacquer that it had been treated with

(The photo is from the Museum of Nature and Man of Padua)

ROME – Discovered in 1931 near Stramaiolo, on the Pinè Plateau, in Trentino, the small reptile Tridentinosaurus, now preserved at the Museum of Nature and Man of the University of Padua, was until recently considered the oldest Italian fossil reptile.Now it turns out that this is not exactly the case.This find owes its importance not only to the indisputable value of fossil evidence of the Permian (from 300 to 250 million years ago), but also to its peculiar appearance due to what was believed a rare soft tissue preservation process:especially the skin.The fossil had a particular colour, very dark, almost unique.It was right the lack of similar fossils which, over the years, has made scientists doubt the method of preserving the find in its fossil state.And this is why research was started to verify this hypothesis:it was decided to X-ray the fossil, to put it simply, and check every detail.And the fossil, at the end of the study, 'confessed' the truth:undergoing conservation it had been lacquered, with a varnish very similar to a lacquer, and this was the reason for the dark color of the skin.

INTERNATIONAL RESEARCH HEADED BY BOLZANO

An international team, supported by the "Living with the supervolcano" research project financed by the Autonomous Province of Bolzano, undertook a multidisciplinary study in search of the smallest details on the composition of the find that could reveal the secrets of the small reptile.The South Tyrolean Museum of Natural Sciences coordinated the project.“Exceptionally preserved fossils are rare, but they can reveal the secrets of coloring, the internal anatomy and physiology of extinct animals offering a clear vision of the organisms of the past", underlines Valentina Rossi, researcher at the University of Cork, leader of the study.“The real surprise comes when, with modern techniques, we unhinge the hidden secrets of fossils“.

THE FOSSIL TOLD THE TRUTH:IT WAS COVERED IN LACQUER

Through the use of powerful microscopes, advanced chemical and diffractometric analyses, including the X-ray microdiffraction single crystal and infrared spectroscopy, the fossil has revealed its secrets:presumably shortly after the discovery, the entire specimen was treated with a lacquer-like coating material.

THE FOSSIL WAS BLACK DUE TO COLORED PAINTING

“Covering fossils with paints and/or lacquers was an ancient method of conservation, in the absence of other, more appropriate, methods of protecting the finds from natural deterioration", explains Mariagabriella Fornasiero, curator at the Museum of Nature and Man of Padua and co-author of the study.However, the analysis of several microsamples extracted from the fossil revealed another truth: the carbonaceous cover does not preserve any trace of biological structures.The chemical composition of the black surface layer corresponds in fact to that of a commercial pigment called “bone black”, still produced today by burning animal bones.For Valentina Rossi:“The puzzle was completed analysis after analysis. What was described as charred skin was just colored paint“.

“THE BLACK WAS NOT SKIN, THE FOSSIL IS NOT THE OLDEST MUMMY IN THE WORLD”

“The peculiar preservation of Tridentinosaurus has perplexed paleontologists for decades,” says Evelyn Kustatscher, researcher at the South Tyrol Museum of Natural Sciences and coordinator of the research project.“Now we know why! What we thought was skin is not, and therefore it is not the world's oldest fossil mummy“.However, the analyzes confirmed the value of the fossil in the reconstruction of the ecosystems of the Permian period (about 280 million years ago);the bones of the hind limbs were in fact found to be authentic, as were some osteoderms, structures similar to crocodile scales, on which researchers are now working in an attempt to reveal the true identity of Tridentinosaurus.

NOW THE TRIDENTINOSAURUS TELLS A NEW STORY

Massimo Bernardi, director of the Museum's research and collections office and co-author of the study, concludes:“Far from being mere displays of the heritage they preserve, museums are dynamic places of research and constant re-signification of finds and practices.Thanks to the effectiveness and rigor of the scientific method, the incessant practice of collecting evidence, formulating hypotheses and questioning them until the most solid theory is built, Tridentinosaurs now tells a new story in which geology and human events intertwine in an unpredictable and fascinating way,”.

For the scientific director of the Museum of Nature and Man, which hosts the find, Fabrizio Nestola, professor of the Geosciences department of the University of Padua, "It is fundamental for a group of researchers to always question themselves, even reaching question what seems to be an established fact.Tridentinosaurus is proof of this:it pushes us to continue investigations to investigate its origins, formulate new hypotheses and answer the questions that surround it.And it is the task of our Museum disseminate the results of new knowledge acquired to the public, animating a debate which, before being scientific, is above all cultural".