First blue feathers found on a fossilized bird

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A new study has discovered the presence of melanosomes coding for blue pigment in fossilized feathers belonging to the Eocene roller Eocoracias brachyptera from the Messel Pit in Germany. The study discovered preserved melanosomes which, depending on their arrangement, code for blue or gray feathers. After comparisons with the feathers of modern rollers, which are more likely to have blue feathers than gray feathers, the researchers determined that the ancient bird's feathers had a deep blue color, representing the first known instance of this color in the fossil record. The study specifies that the blue color was a non-iridescent structural color, meaning that the feathers got their color from the reflection of light off of specific structures in the feathers either instead of or in addition to the pigments present within the feathers, with the lack of iridescence meaning that the feather color didn't change based on the angle the light shone on the feather. This research is significant, as blue feathers are extremely uncommon in bird lineages, with only about 10 modern species possessing a similar coloration to that of E. brachyptera. The presence of melanosomes coding for blue feather color also decreases the accuracy of predictive models of fossil color from 82% accurate to 61.9% accurate, as these same structures were originally believed to only code for gray feather color in fossilized species. Here is an image of the fossil of E. brachyptera used in this study, a reconstruction of the genus with the discovered feather color, and a link to the paper describing the new study.




Paper (abstract only): https://royalsocietypublishing.org/lookup/doi/10.1098/rsif.2018.0921

[Ravonium]

Thanks for sharing; this is an excellent find! Only thing I'm wondering now is why there's an absence of melanosomes in Mesozoic animals that don't produce black, white or red/orange.