The plumage of the world's first known bird contained at least some black, researchers report.

A team led by Ryan Carney at Brown University in Providence, Rhode Island, examined a fossilized feather (pictured) from the bird Archaeopteryx, which lived 150 million years ago. Using electron microscopy, they spotted rod-shaped, pigmented organelles called melanosomes inside preserved cells. Statistical comparison of the shape of these organelles with those of 87 extant birds identified similarities to melanosomes from birds with black plumage.

The melanin responsible for black pigmentation provides structural support as well as colour. The authors suggest that this would have improved the feathers' strength and durability — an advantage during this early evolutionary stage of dinosaur flight.

Nature Commun. (2012)