Fossilized Dinosaur Feathers Are Confirmed To Preserve True Colors

Paleontologists examine the chemical signatures of fossilized feathers and find they are remarkably similar to modern birds

A close-up look through the scanning electron microscope of fossilized feather melanosomes. (Image from Lindgren et al. 2015 Scientific Reports)

A close-up look through the scanning electron microscope of fossilized feather melanosomes. (Image from Lindgren et al. 2015 Scientific Reports)

What color was a Velociraptor? A little over 5 years ago, many thought paleontologists just could not answer that question. After all, there may be amazing fossils of carbonized feathers, but they don’t get preserved in their original colors after being buried under tons of sediment for millions of years. It was not until research in early 2010 indicated that structures visible in exquisitely preserved dinosaur feathers from China resemble similar sacs that dictate feather color in modern birds. Then paleontologists realized feather color of extinct dinosaurs could potentially be known for certain.

[fsbProduct product_id=’885′ size=’180′ align=’right’]Since then, a number of publications have examined well-preserved dinosaur feathers and looked at the structures of their melanosomes—small organelles found in bird feathers and mammal hair that are different shapes depending on the color of pigment they contain. Rod shaped ones are called eumelanosomes and are found in black feathers while circular phaeomelanosomes store pigment in red feathers—and also red human hair. Colors like blue and yellow, for example, cannot be preserved though, because those colors are caused by specific proteins that breakdown too easily to be discovered in fossils that are tens of millions of years old.

Although the structures in fossilized feathers look just like melanosomes in bird feathers, skeptics have argued that what paleontologists are labeling a ‘melanosome’ could just be a type of fossilized bacteria of a similar shape. A new study from Johan Lindgren at Lund University and a team of co-authors in Scientific Reports out today uses chemical analysis methods to confirm that these structures are in fact melanosomes and allow paleontologists to say with certainty what color feathered dinosaurs were.

The team of international researchers went beyond using structural analysis and compared the chemical signatures of modern and fossil eumelanin in a well-preserved specimen of the Jurassic early bird relative Anchiornis from China. What they found was almost identical—the chemical makeup of what looked like fossil “eumelanosomes” (black pigments) was virtually identical to that found in living birds.

The specimen of Anchiornis analyzed in this study (Image Credit: Thierry Hubin/RBINS)

The specimen of Anchiornis analyzed in this study (Image Credit: Thierry Hubin/RBINS)

They also tested the chemical signatures of bacteria to compare to the fossil melanosomes, but the chemical signatures did not match. Study co-author Ryan Carney from Brown University explains: “This is animal melanin, not microbial melanin, and it is associated with these melanosome-like structures in the fossil feathers.” With this information paleontologists can be more confident in the future about using fossilized melanosomes to distinguish the color of dinosaurs from preserved feathers.

Source: Molecular composition and ultrastructure of Jurassic paravian feathers

Attribution: Forbes

 
 

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