February 4th

2010 – Scientists interpret dinosaur color 

The discovery of dinosaur feathers made the ancient creatures more real to us than ever before. But the story of how scientists solved one of the biggest mysteries of the prehistoric world begins not with birds or dinosaurs, but with squid. A Yale University grad student named Jakob Vinther discovered cells known as melanosomes in a fossil squid’s ink sac. The shape of the melanosomes matched those of modern-day squid, which allowed Vinther to see that prehistoric cephalopod also carried black ink. But the impact of his find was more important than confirming that squid ink hadn’t changed. If pigments preserved in melanosomes could survive fossilization, perhaps there was a way to identify the colors of dinosaurs and other prehistoric creatures.

Anchiornis huxleyi / Science Codex
Anchiornis huxleyi / Science Codex

Vinther sought the services of Yale’s Curator of Vertebrate Paleontology, Derek Briggs, as well as bird expert Richard Prum, and paleontologist Julia A. Clarke for a trip to China to seek out feathered dinosaur samples. Taking tiny samples of the fossils, they would attempt to map the melanosomes by shape and determine the color of a feathered dinosaur. Convincing museums to take samples off priceless fossils is not an easy business, but after several attempts at different institutions, the team was successful in acquiring some excellent samples from an unidentified feathered dinosaur.

Back in New Haven, Vinther was isolating melanosomes but needed assistance identifying the various shapes. He contacted Matthew Shawkey, a melanosome expert, to help the team move forward. After long study of the melanosome structure, Vinther matched the samples to their location on the body of the little dinosaur. Clarke had determined that the animal was a specimen of the crow-sized Anchiornis huxleyi, a “near bird” dedicated in honor of Thomas Henry Huxley.

Finally, avian artist extraordinaire Michael DiGiorgio was given the task of painting by prehistoric number. His full-color restoration was truly astounding. Anchiornis was mostly gray and black in color, but sported a rufous red crest on the back of its head, and red spots on its cheeks. On all four of its limbs, long feathers were adorned with white stripes and black spots. Through this process of identification, humanity was able to see for the first time through the eyes of the dinosaur and into the actual colors of their primeval world.

Melanosomes and physical evidence don’t tell the entire story of coloration in feathers. The bright colors we see in parrots and flamingos are derived largely from elements in the birds’ diets. The shimmering iridescence of hummingbirds and peacocks are produced by light bouncing off the physical structure of the feather itself. So melanosomes are only a first step to understanding prehistoric coloration, but we are approaching a vision of the past that is more accurate and precise than ever before. Only with a coalition of paleontologists, biologists, artists, and specialized experts can these riddles be solved. As techniques used to study the ancient world blend with the latest technologies, scientists can picture the prehistoric world in continually refined splendor.

Because dinosaurs were related to birds and reptiles, paleontologists speculated that they could see in color much as their modern-day relatives do. But the colorful plumage of the feathered dinosaurs suggests that Mesozoic color vision is a near-certainty. These colored frills and striped feathers must have been carrying the same messages that feathers carry today: I’m an attractive mate, or stay out of my territory, or even, I’m still a juvenile. It’s also plausible to think that males and females were differentiated by color pattern. It now appears that the hunt for dinosaur color has only just begun. As new techniques develop and more specimens are examined, we can begin to imagine dinosaur books showing the extinct animals as accurately as today’s tigers, falcons, and geckos.

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