Paleontologists at the University College Cork and the University of Bristol have discovered the pigment melanin in fossil, making scientists reconsider the colors of ancient birds, reptiles, and dinosaurs.
So far, studies found melanin in the skin of fossils – in the form of fossilized granules (melanosomes). But a new study found something impressive: not only the skin, but also the liver, lungs and spleen contain melanosomes. This means that melanosomes don’t provide only information on the color of fossils.
The study was published this week in the journal Nature Communications. The lead author of the study is Dr. Maria McNamara, collaborating with Ph.D. student Valentina Rossi (both at the University College Cork), Dr. Paddy Orr (University College Dublin) and a team of paleontologists from Japan and the UK.
The team started examining modern frogs and looked at the internal tissue using powerful microscopes and chemicals. They discovered that there is an abundance in internal melanosomes.
Melanin Might Have a Different Purpose After All
In fossils, Dr. McNamara explains that these melanosomes could be the majority of the ones that were preserved in time. There is also another question: did pigment have other roles than coloring the skin or feathers of the animals?
In decay experiments, the team analyzed fossils to see if the melanosomes in the fossils were from the skin. They wanted to know if during the fossilization process they leaked into other body parts. But, thankfully, there is an obvious difference between the melanosomes from internal organs and the ones from the skin, explains Dr. McNamara:
“The size and shape of skin melanosomes is usually distinct from those in internal organs. This will allow us to produce more accurate reconstructions of the original colours of ancient vertebrates.”
The next step is for researchers to find out what made melanin evolve and what is its actual purpose, concluded McNamara: “We’ve always thought oh its for colour, oh its for sexual selection and camouflage, but if it’s in all these internal organs then maybe it evolved for a completely different purpose.”
Andre Blair s is the lead editor for Advocator.ca. He holds a B.A. in Psychology from the University of Toronto, and a Master of Science in Public Health (M.S.P.H.) from the School of Public Health, Department of Health Administration, at the University of North Carolina at Chapel Hill. Andre specializes in environmental health, but writes on a variety of issues.