Melanosomes: Dinosaurs in White, Orange, and Grey

Anchiornis huxleyi

What color was a Tyrannosaurus Rex? What about a triceratops, or a pterodactyl? Pink and yellow, or more earthy shades, like brown and grey? Since the discovery of the dinosaur, their hues, vibrant or otherwise, were a mystery. This was until the discovery of melanosomes.

Melanosomes are "pigment filled sacs" that determine the colors of the feathers of birds. In essence, the cells carry the color of the species within them, in the form of melanin. In 2009, a researcher at Yale, by the name of Dr. Prum, discovered that these melanosomes could be kept in a fossil for millions of years.

These melanosomes were so well preserved because instead of being on the outside of the feathers, they were contained within. This meant that they were protected from damage as long as the feathers remained intact.

The Yale scientists conducted studies on several ancient dinosaur feather fossils, and discovered that it was possible to determine the color of the fossil from the melanosomes. Therefore, they teamed up with paleontologists from the Beijing museum of Natural History and Peking University. These scientists were led by Fucheng Zhang. Together, they took the fossil of a Anchiornis huxleyi, which lived 150 million years ago during the "Middle Jurassic" into the "Late Jurassic". This tiny dinosaur had very long legs, which were covered with feathers (as were its arms). They took out twenty nine "chips" of the fossil to examine under a microscope, and found that these pieces contained melanosomes.

After finding the melanosomes in the dinosaurs, the scientists had to compare these melanosomes to the melanosomes found in modern birds. They already knew that this dinosaur had two different types of melanosomes, called eumelanosomes and phaeomelanosomes. Eumelanosomes are found in dark colors, such as black, grey, and brown. The phaeomelanosomes can be found in feathers that range in shade from yellow to red. However, the scientists didn't want a general guess of the colors, they wanted to find the real answers. Thus, they contacted Matthew Shawkey, a scientists who had already done in depth studies of melanosomes in living birds. They matched the melanosomes in the Anchiornis with those of other birds, and discovered that the feathers on the birds arms and legs were black and white, while its head was covered with a magnificent orange plume.

After this discovery, they tried to replicate this process with other fossils that had the "dinosaur fuzz" feathers. They were able to find the color of the Sinosauropteryx's tail (reddish with white rings). They could also make educated guesses about the pigments of the sinonithosaurus, and the confuciusornis, because their feathers were not preserved as well.

This is a remarkable study, and who knows, maybe some day we'll learn that the Tyrannosaurus Rex was bright pink!

The height of an Anchiornis compared to the height of a human being.

The sinosauropteryx

Sources:
http://www.nytimes.com/2010/02/05/science/05dino.html?ref=dinosaurs
http://scienceblogs.com/notrocketscience/2010/01/what_colours_were_dinosaur_feathers.php
http://blogs.smithsonianmag.com/dinosaur/2010/02/05/dinosaurs-now-in-living-color/
http://blogs.smithsonianmag.com/dinosaur/2010/01/28/fossil-feathers-may-preserve-dinosaur-colors/
http://en.wikipedia.org/wiki/Anchiornis
http://i.livescience.com/images/ig59_Sinosauropteryx_09.jpg