Alleged tissue in reptile fossil is just black paint – 02/25/2024 – Science

A study published on the 16th in the journal Paleontology points out that the tissue remains preserved in the body of a fossil reptile from Italy were forged using black paint.

The fossil, known as Tridentinosaurus antiquuswas excavated from sediments estimated to be Early Permian (approximately 280 million years ago) from the Italian Alps.

Its exceptional preservation, with traces of what would have been soft tissues, such as skin and muscles, made the material one of the most emblematic of the period in the country.

However, what was previously believed to be a millions-of-year-old fossilized skin mark is actually black paint, which was used to outline the animal’s outline, according to researchers at UCC (University College of Cork), in Ireland.

The discovery of T. antiquus occurred in 1931 in the Pinè Valley region, in northern Italy (30 km from Trento), and the fossil was widely studied as one of the representatives of the initial lineages of reptiles on the continent, part of the group known as Protosauria.

Such studies were carried out without the use of modern paleontological analysis techniques, which emerged in the last 20 years. Therefore, scientists who studied it in the past did not identify that the impression was, in fact, forged.

“The origin of the black trace could not be determined by analysis with the naked eye or using a normal microscope”, explains researcher from the School of Biology, Earth and Environmental Sciences at UCC and first author of the study, Valentina Rossi. “Only in recent years, with the development of non-destructive techniques for studying fossils, have we been able to identify their true composition.”

The fossil’s shape resembles a lizard, with long arms and legs and five fingers and toes. The bones preserved in the specimen —femur, tibia and fibula fragments and osteoderms, which are calcified dermal plates—, however, are difficult to visualize, which led experts to consider the black outline as some type of charring of the body —a process in which the carbon present in the rock matrix replaces living tissues.

Using a combination of scanning electron microscopy, spectroscopy (measurement of the radiation emitted by molecules) and X-rays, the team led by Rossi identified that the carbon molecules in the animal’s outline are not of natural origin, that is, they are not are elements present in the soft tissues of living organisms.

Furthermore, the way the molecules are organized as granules of different sizes, and not in three-dimensional cells, as melanocytes —pigment cells in animal tissues— are known, was also another clue that helped unravel the true nature of the fossil.

“My initial step in this research was to approach the investigation with an open mind, that is, without any preconceived idea of ​​the composition of the black outline, and to test whether it was of natural origin. When I realized that it had no biological structure or biomolecular signature [traços deixados por proteínas e outras moléculas produzidas pelos seres vivos] In material, I expanded the search to non-fossil materials, such as glues, resins and paints that are sometimes used for paleontological preparation,” he said.

In the article, the authors conclude that the specimen “does not present the basic characteristics of a vertebrate fossil with preserved tissues”, which generally includes a condition of either very rapid fossilization (a death event followed by burial, for example) or high sulfur rates (aquatic environments with low sediment movement).

In these cases, it is common to find the impression or even elements of skin and muscles of the preserved animal. Some of these examples are the fossils found in the Araripe Basin, the largest fossil basin in the country, between the states of Ceará, Piauí and Pernambuco, or the Lagerstätte formation, in Germany, where the famous Archeopteryx fossil, one of the most primitive birds, was found. known.

It is uncertain, however, how the paint ended up there, whether it was something done intentionally by the fossil’s discoverer to increase its scientific value or whether this occurred later, when the material was taken to the collection of the Museum of Nature and Man. , in Padua (Italy). Rossi states that any attempt to explain what happened would be speculative, at best.

In any case, the new discovery shook paleontological knowledge in Italy and, above all, shed light on an increasingly common problem of falsification of fossils and historical artifacts. “Certainly, it is necessary to rethink the evolutionary and paleontological importance of T. antiquus now that it has been determined that the outline of the fossil is not natural. But the fact that there are some preserved bones is encouraging, as it could help understand the evolution of that group of reptiles and even lead to new fieldwork to look for other fossils,” he said.