Melanosomes!

Did you know it is now possible to say something about what color a bird's dinosaur's feathers were, from looking at its fossil?

Whoa. I sure didn't. And apparently it is pretty new:

A year ago, Canadian paleontologists described some of the first examples of feather coloring in the age of dinosaurs. They were found in 70 million-year-old amber preserving 11 specimens with a wide variety of feather types, some in bright colors. A different pigmentation method produces the brighter-colored features of, say, cardinals.

Here's how the article starts:

Sexual drive, not flight, may have been the main reason for the feather color and pattern of Microraptor, a four-winged dinosaur that lived some 130 million years ago in what is now northeastern China.

New research by American and Chinese scientists shows that the animal had a predominantly glossy iridescent sheen in hues of black and blue, like a crow. This is the earliest known evidence of iridescent color in feathers. The animal also had a striking pair of long, narrow tail feathers, perhaps to call attention to itself in courtship.

In the study, published online Thursday in the journal Science, the researchers compared the patterns of pigment-containing cells from a Microraptor fossil with those of modern birds. The shape and orientation of these cells, known as melanosomes, were narrow and arranged in a distinctive pattern, as in the case of living birds with glossy feathers.

Only recently has it become possible with scanning electron microscopes to examine well-preserved fossil remains of melanosomes, so tiny that a hundred can fit across a human hair. Such pigment agents in many birds are generally round or cigar-shaped, but these were especially narrow, like those of blackbirds. The iridescence arises when the melanosomes are organized in stacked layers.

Read all the words.