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Sinosauropteryx** is the first fossil dinosaur to have its color scientifically established.
Illustration courtesy James Robins
Chris Sloan
National Geographic magazine paleontology editor, for National Geographic News
Published January 27, 2010
Pigments have been found in fossil dinosaurs for the first time, a new study says.
The discovery may prove once and for all thatdinosaurs' hairlike filaments—sometimes called dino fuzz—are related to bird feathers, paleontologists announced today. (Pictures: Dinosaur True Colors Revealed by Feather Find.)
The finding may also open up a new world of prehistoric color, illuminating the role of color in dinosaur behavior and allowing the first accurately colored dinosaur re-creations, according to the study team, led by FuchengZhang of China's Institute for Vertebrate Paleontology.
The team identified fossilized melanosomes—pigment-bearing organelles—in the feathers and filament-like "protofeathers" of fossil birds and dinosaurs from northeastern China.
Found in the feathers of living birds, the nano-size packets of pigment—a hundred melanosomes can fit across a human hair—were first reported in fossil birdfeathers in 2008.
That year, Yale graduate student Jakob Vinther and colleagues, using a scanning electron microscope, discovered melanosomes in the dark bands of a hundred-million-year-old feather. In 2009 Vinther's group went on to show that another fossilized feather would have been iridescent in a living bird, due to microscopic light-refracting surfaces created by stacked melanosomes.
Theseearlier findings proved it was possible for melanosomes from dinosaur times to survive in fossils.
But until now no one had found the pigments in dinosaurs—other than birds, which many paleontologists consider to be dinosaurs. And no one had used melanosome shape and density to infer color.
(Related quiz: Test your dinosaur IQ.)
End of Dinosaur-Bird Debate?
Even as thehundred-million-year-old bird melanosomes were being announced in 2008, the team behind the January 2010 report was using a scanning electron microscope to study minute details of feathered birds and dinosaurs found in Liaoning Province, China, a region famous for yielding thousands of exquisitely preserved animals that lived between 131 and 120 million years ago (prehistoric time line).
The Liaoning projectput the team in a unique position to attempt the first melanosome discovery in dinosaurs.
"When we saw the Vinther paper, we said, Hey, look at this—and we found melanosomes immediately," said study co-author Mike Benton, a paleontologist at the University of Bristol in England.
The new study, published online today by the journal Nature, is "scientifically sound," said Hans Dieter-Sues, apaleontologist at the Smithsonian Institution's National Museum of Natural History in Washington, D.C., who was not involved in the research.
"I think the researchers really are looking at the fossilized remnants of melanosomes," he added in his email.
Among the fossil dinosaurs studied were several that were preserved with dino fuzz, such as the turkey-size carnivore Sinosauropteryx.
Someresearchers argue that these controversial hairlike filaments, each about the width of a human hair, are fossilized internal collagen and not related to feathers. (Related: "'Feathered' Dinosaur Was Bald, Not Bird Ancestor, Controversial Study Says.")
The results reported today show that the filaments are packed with melanosomes in the same way as modern feathers.
"These filaments areprobably the evolutionary precursors of true feathers," Benton said.
The Smithsonian's Sues added, "I think that one can safely say that this find invalidates some recent attempts to deny the existence of protofeathers in birdlike dinosaurs by claiming (without compelling evidence) that they are degraded collagen fibers."
University of Maryland paleontologist Thomas Holtz agreed, saying it's now...
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