🦴 Bacteria preserved pterosaur molecules for 113 million years

An international team led by Curtin University analyzed a 113-million-year-old pterosaur wing bone from Brazil, preserved in three dimensions with rare chemical traces. Researchers identified specialized bacteria that played a key role in this exceptional fossilization process.

After the animal died, it sank to the bottom of an ancient ocean. Microbes, including sulfur-oxidizing bacteria, broke down its soft tissues and triggered mineralization around the body. This chemical reaction, combined with the particular marine conditions, locked the bone structure in exquisite detail for more than 100 million years.


The study, published in iScience, marks a first: thanks to this preservation, steroids could be extracted from the fossil. These hormones reveal that the animal fed on fish or squid. Professor Kliti Grice, lead author, emphasizes that the preservation of these organic compounds is exceptional. She notes that oxygen, far from destroying the fossil, helped safeguard it through microbial activity.

This preservation mechanism by microbes is not isolated; it appears to occur at other fossil sites around the world. Scientists are even describing a new type of exceptionally preserved deposit, called a Lagerstätte. Pterosaurs, the first vertebrates to master active flight, had hollow bones like modern birds, a feature that favored their fossilization under ideal conditions.

The results open promising perspectives for molecular paleontology. By analyzing the chemical traces left behind by microbes and tissues, researchers can reconstruct the ancient environment and lifestyle of these extinct creatures. This refined approach overcomes the limitations of studying only skeletons.