Fossil forgery really gets under the skin

A team led by a UCC palaeontologist has unearthed the shocking and disappointing truth behind a 280 million year old reptile fossil in Italy.

Dr Valentina Rossi of the School of Biological, Earth and Environmental Sciences at UCC, and her team of Irish and Italian researchers recently found an iconic fossil of a lizard in the Italian Alps to be partially fake.

The new research, published in the scientific journal Palaeontology, reveals that the reptile-like fossil, renowned for its remarkable preservation, is mostly just black paint on a carved lizard-shaped rock surface.

The important discovery was made thanks to the use of powerful microscopes and advanced chemical techniques.

Known as Tridentinosaurus, the fossil was discovered in 1931 in Trentino Alto-Adige.

It was then acquired by the University of Padua where it was initially described as an exceptionally preserved specimen due to evidence of a carbon-rich dark-coloured matter on the surface of the rock understood to be skin.

Commenting on the specimen, Dr Rossi said the purported fossilised skin has been celebrated in articles and books but never studied in detail.

According to Ms Rossi, the somewhat unusual preservation of the fossil had left many experts uncertain about what group of reptiles the lizard-like animal belonged to and more generally its geological history.

“Fossil soft tissues are rare, but when found in a fossil they can reveal important biological information, for instance, the external colouration, internal anatomy, and physiology,” explained Dr Rossi.

“The answer to all our questions was right in front of us, we had to study this fossil specimen in detail to reveal its secrets – even those that perhaps we did not want to know,” she added.

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 typical in the past and is sometimes still used to preserve a fossil specimen in museum cabinets and exhibits today.

Dr Rossi’s team was hoping that beneath the coating layer, the original soft tissues would still be in good condition, allowing them to extract meaningful palaeobiological information.

However, the analysis of several soft tissue samples revealed that, at a microscopic level, there was no trace of biological structures. At a chemical level, the material matched the chemistry of a carbon-based manufactured pigment called ‘bone black’, still produced today by the burning of animal bones.

But Dr Rossi says all is not lost as the fossil is not a complete fake. The bones of the hindlimbs, in particular the femurs appear to be genuine.

Also, 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.

Dr Rossi believes future discoveries and research will reveal the true identity of the ancient reptile.

“Fossil forgeries are a serious problem in palaeontology, and these specimens can pass undetected even to the most expert eyes; this is especially true for specimens that were acquired by a museum in historical times,” said Dr Rossi.

She continued: “Modern and rigorous scientific methods are our best weapon against the illegal practice of forging fossils. Reporting such specimens is our duty as scientists.”