UCC scientists find ginger pigment in ancient frog fossils

6 Oct 2023

Prof Maria McNamara and Dr Tiffany Slater of UCC. Image: Daragh Mc Sweeney/Provision

The researchers said this discovery will paint a more accurate picture of ancient animal colour and could explain why this particular pigment evolved in animals.

Palaeontologists at University College Cork (UCC) claim to have found the first molecular evidence of the ginger pigment in the fossil record – in frog fossils that are 10m years old.

The UCC researchers found molecular fragments of phaeomelanin – the pigment that produces ginger colouration – in these ancient fossils, which could provide new insight when reconstructing the colours of long-extinct organisms.

The study – published today (6 October) in Nature Communications – was led by UCC palaeontologists Dr Tiffany Slater and Prof Maria McNamara, who worked with an international team of scientists from Japan, China and Sweden.

“This finding is so exciting because it puts palaeontologists in a better place to detect different melanin pigments in many more fossils,” Slater said. “This will paint a more accurate picture of ancient animal colour and will answer important questions about the evolution of colours in animals.

“Scientists still don’t know how – or why – phaeomelanin evolved because it is toxic to animals, but the fossil record might just unlock the mystery.”

Naturally, fossils degrade over time, so the team performed experiments on black, ginger and white feathers to see how phaeomelanin pigments degrade during the fossilisation process.

“Fossils are invariably altered by the ravages of heat and pressure during burial, but that doesn’t mean that we lose all original biomolecular information,” McNamara said. “Our fossilisation experiments were the key to understanding the chemistry of the fossils, and prove that traces of biomolecules can survive being cooked during the fossilisation process.

McNamara said that there is “huge potential” to explore the biochemical evolution of animals by using the fossil record.

McNamara was one of the researchers behind another UCC discovery last year, which solved an ancient mystery of what caused the deaths of hundreds of frogs in a particular area around 45m years ago– the only logical answer appears to be that they “died during mating”.

She also spoke to SiliconRepublic.com in March 2022 about how fossil records can unlock the secrets of animal evolution.

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Leigh Mc Gowran is a journalist with Silicon Republic