Frogs help Irish scientists make leap in reconstructing the appearance of extinct animals

Irish scientists have made a giant leap in the reconstruction of the appearance of extinct animals - thanks to fossilised frogs.

Frogs help Irish scientists make leap in reconstructing the appearance of extinct animals

Irish scientists have made a giant leap in the reconstruction of the appearance of extinct animals - thanks to fossilised frogs.

In what University College Cork describes as a world-first, two UCC palaeontologists have discovered a new way to recreate the anatomy of ancient vertebrate animals by analysing the chemistry of tiny fossilised sub-cell units in the internal organs of the extinct fossilised animals.

They believe their work mapping the preserved chemical signals found in these fossils has “profound implications” for how scientists will interpret the internal anatomy of fossilised animals, and thereby recreate the look of these ancient animals.

A melanosome is a tiny organism found in animal cells. It is the site for the synthesis, storage and transport of melanin, the most common light-absorbing pigment found in the animal kingdom.

Until recently, most studies on fossil melanin focused on the skin and feathers and used certain techniques to map the pigment to reveal the external look of the ancient animal.

But research, led by UCC’s Valentina Rossi and her supervisor, Dr Maria McNamara, in collaboration with chemists from the US and Japan, has allowed them to 'peer inside' the animals.

Maria Mc Namara, Senior Lecturer and Valentina Rossi, PhD student with a fossil sample at the School of Biological, Earth and Envirnomental Sciences UCC. Pic Michael Mac Sweeney/Provision
Maria Mc Namara, Senior Lecturer and Valentina Rossi, PhD student with a fossil sample at the School of Biological, Earth and Envirnomental Sciences UCC. Pic Michael Mac Sweeney/Provision

They used cutting-edge synchrotron techniques - a powerful source of X-rays - to analyse the chemistry of the fossil and modern melanosomes.

It allowed them to detect minute quantities of different metals in the melanosomes, and effectively map the location and shape of organs such as the lungs, liver, gut and heart.

Unexpectedly, the study also showed that melanin is abundant in internal organs of modern amphibians, reptiles, birds and mammals, and their fossil counterparts, which will allow scientists to compare findings with fossils to modern animals.

“This discovery is remarkable in that it opens up a new avenue for reconstructing the anatomy of ancient animals. In some of our fossils we can identify skin, lungs, the liver, the gut, the heart, and even connective tissue.

10 million-year-old fossil tadpole from Libros, Spain and X-ray map showing elevated levels of titanium in the skin, eye and especially the liver. X-ray fluorescence map copyright Valentina Rossi.
10 million-year-old fossil tadpole from Libros, Spain and X-ray map showing elevated levels of titanium in the skin, eye and especially the liver. X-ray fluorescence map copyright Valentina Rossi.

“What’s more, this suggests that melanin had very ancient functions in regulating metal chemistry in the body going back tens, if not hundreds, of millions of years,” Dr McNamara said.

The new research arose out of the team’s discovery last year of internal melanosomes on fossil frogs. They had a hunch that these features would be more widespread across vertebrates but they didn't realise it would be different in different organs.

Their study is published in the journal, Proceedings of the National Academy of Sciences of the United States of America.

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