Key Points

The study, published in the journal Geobiology, examined 300-million-year-old fossilised droppings, or "coprolites," mostly from the Mazon Creek fossil site in the United States, according to a statement released Friday by Australia's Curtin University.

The coprolites were already known to contain cholesterol derivatives, which is strong evidence of a meat-based diet, but the new research explored how those delicate molecular traces were preserved and survived the ravages of time, reports Xinhua news agency.

Usually, soft tissues are fossilised due to phosphate minerals, but scientists from Australia, the United States, Sweden and Germany found molecules were preserved thanks to tiny grains of iron carbonate scattered throughout the fossil, acting like microscopic time capsules.

"Fossils don't just preserve the shapes of long-extinct creatures; they can also hold chemical traces of life," said study lead Madison Tripp, adjunct research fellow at Curtin's School of Earth and Planetary Sciences.

"It's a bit like discovering a treasure chest, in this instance phosphate, but the real gold is stashed in the pebbles nearby," Tripp said, adding the findings deepen scientists' understanding of molecular preservation, crucial to gaining insights into the ancient world.

"Carbonate minerals have been quietly preserving biological information throughout Earth's history," said Curtin University Professor Kliti Grice, adding that expanded analysis of diverse fossils spanning different species, environments, and eras confirmed consistent mineral-molecule preservation patterns.

Understanding which minerals best preserve ancient biomolecules lets scientists target fossil searches more effectively, focusing on conditions that increase the chances of finding molecular clues about ancient life, Grice said.

Researchers said the findings could help build richer pictures of past ecosystems, including diets, interactions and decomposition processes.

"It brings prehistoric worlds to life in molecular detail," Grice said

- IANS