While the dinosaurs of Jurassic Park were scaly, greenish-brown monsters, dinosaurs in real life may have looked more like flamboyantly feathered peacocks.
A study by Yale researchers Jakob Vinther GRD ’11 and Richard Prum, which appeared in the journal Science earlier this month, has paved the way for the first true color images of a dinosaur. Vinther, a student in the geology and geophysics department, and Prum, an ornithologist and a professor of ecology and evolutionary biology, said they hope the images will revolutionize dinosaur research.
“This is a new chapter in the study of dinosaurs,” Vinther said. “In the next 10 years, we’ll see a number of dinosaurs in real color.”
Vinther was studying fossilized squid ink sacs under an electron microscope when he discovered round objects containing pigments within the sacs. While scientists had previously found similar objects in fossilized dinosaur feathers, they thought the objects were the remains of bacteria. But Vinther said he suspected that the objects, called melanosomes, came from the dinosaurs themselves; if true, this would finally allow scientists to discover what colors dinosaurs were.
“When I saw these pigments in the squid, I thought, ‘There is a chance we could find these elsewhere because, chemically, they are the same [in many organisms,]’ ’’ Vinther said.
Vinther and his team brought their results to Matt Shawkey, a professor at the University of Akron in Ohio. Shawkey compared the melanosomes found in the dinosaur fossils to those of modern birds, and he found that the scientists could recreate the dinosaurs’ feather colors with 90 percent accuracy, Vinther said. But the scientists had to find the exact mixture of melanosomes in the feathers to be able to color the dinosaurs accurately, Vinther said.
“Even if you look at a sparrow, you can see various nuances of brown and gray made by specific configurations and concentrations of pigments,” he said.
Vinther and his team decided to use their research to unveil the colors of the Anchiornis huxleyi, a winged dinosaur that lived in China more than 150 million years ago, during the Jurassic period. Notably, the coloring of the Anchiornis huxleyi, which had a reddish-orange crest and spotted wings, resembles the patterns on a Spangled Hamburg chicken, a species developed in Holland and Gemany, Prum said.
Most fossils found in North America are useless for melanosome testing because the pigments were not preserved, Vinther said. But ancient, slow-flowing lakes in China, which allowed animals to be buried quickly without being disturbed by currents, preserved the pigments in the fossils for millions of years, he said.
While Chinese officials have restricted access to the fossils of other dinosaurs, Vinther said he remains optimistic that scientists will be able to determine the colors of more dinosaurs.
Prum said the “bold” and “spectacular” coloring of the dinosaur’s feathers indicates that, rather than being used for flight, feathers were originally used to communicate and to find mates. According to accepted theories, Prum said, feathers began as tubes, later evolving into tufts; eventually, they developed into the complex, branch-like structures observed in modern birds, he said.
Feathered dinosaurs first appeared in the late Jurassic period, Prum said. The discovery of “dino-fuzz” on the skin of dinosaur fossils in the late 1990s proved that theropods — a suborder of dinosaur that includes Anchiornis huxleyi, as well as Tyrannosaurus rex — were actually covered with feathers, he added.
“The most important result from this is to realize that birds are more dinosaurian than we thought.” Prum said. “At the same time, dinosaurs are also more ‘birdy’ than we suspected.”
The Yale-led team’s discovery will change the public’s image of dinosaurs, said Douglas Erwin, president of the Paleontological Society and curator of the Smithsonian’s National Museum of Natural History.
“People have colored dinosaurs in the past, but these colors were nearly entirely imaginary,” Erwin said. “Right now, I even have a dinosaur on my desk that’s purple with white spots.”
But Erwin added that due to the cost and infrequency of updating dinosaur displays, colored feather dinosaurs may not extensively appear in museums for decades.
Vinther said he hopes melanosome-based analysis will be used to add color to ancient shells, insects, ichthyosaurs and mammals in the future.
Other members of the research team included Yale professor and director of the Peabody Museum of Natural History Derek Briggs and scientists from the University of Texas — Austin, the University of Akron, Peking University and the Beijing Museum of Natural History. The team received grants from the National Geographic Society and the National Science Foundation.