Bird fossil sheds new light on ‘grey area’
A fossilised bird that lived about 48 million years ago has had a ‘yin yang’ impact on modern efforts to reveal the true colours of ancient animals.
The oldest fossil evidence of blue feathers ever found belong to the Eocoracias brachyptera, recovered from the famous Messel Pit in Germany, where the bird was entombed during the Eocene period, which endured from 56 to nearly 34 million years ago.
A just-published study in Journal of the Royal Society Interface reveals that researchers can confirm the blue colour of E. brachyptera’s feathers because they are comparable with those of its modern relatives – the rollers.
Tiny structures preserved in the fossilised feathers resemble those that give modern birds either blue or grey hues, depending on their arrangement.
As far as is known, blue feathers have been uncommon through time. But since modern rollers are far likelier to have blue than grey feathers, the researchers conclude that the ancient bird was a deep blue.
It is the first time that such a feather colour has been reconstructed from the fossil record. But it has rather thrown prediction models of fossil colours into a bit of a tiz – because earlier methods assumed that fossil structures responsible for blue and grey produced only grey.
Although the finding reduces the accuracy of earlier colour predictions by about 20 percent, scientists say it provides a valuable new context for understanding what ancient animals really looked like.
According to National Geographic, unveiling the colours of ancient animals is a major growth industry. Key to the colour revolution was the discovery that microscopic pigment sacs called melanosomes could fossilise. Melanosomes contain two varieties of the pigment melanin, which can create hues from red-brown to black. Melanosomes have been recovered from many prehistoric creatures, from birds to non-avian dinosaurs and even marine reptiles.
Bird feathers can also get their colour from the fine structure of their feathers, rather than directly from pigments.
Natural Images 2019