Vinther and his colleagues continue to search for more clues about coloration. By studying the structures of melanosomes' arrangement in more recent feathers, they were able to deduce when feathers would have iridescence, lending another level of sheen, and even purples, blues and greens to some surfaces. In a 2009 paper in Biology Letters, the team described evidence of iridescence they found on fossilized middle Eocene epoch feathers based on these structures, but older bird and dinosaur feathers have yet to yield any shiny clues.
Given these organelles' prevalence, their discovery in fossilized feathers will likely open the door to a rush of new coloration studies. "We can definitely take this to look at skin, as well," Vinther says. As Benton noted, however, although the pigmentation is widespread in reptile and fish scales today, it is unusual to find remnants of organic material in dinosaur fossils. What we know about their skin is generally deduced from imprints left in surrounding material, which would not contain the organelles needed to predict coloration.
Colorful clues
In the meantime, even if only the wings and tails of certain feathered dinosaurs and early birds can be colored in, it will help researchers deduce much more about extinct animals' ecology and behavior—and also about other physiological details such as vision. As Vinther notes, "If you do find spectacular colors in these animals, then you know they had an ability to see more colors than just black and white."
Beyond coloration, the presence of these melanosomes in early Cretaceous dinosaurs helps to confirm the presence of protofeathers in some dinosaurs, which some have argued were simply connective tissue. The Sinosauropteryx that they studied, one of the earliest Sinosauropteryxs to have featherlike structures had, what Benton described as "a very clear rim of feathers running down the head, down the back and along the tail."
These adornments were not feathers in the modern sense, such as those found on modern turkeys and peacocks. "These are very simple structures," Benton said. "They're sort of bristles" which were four to 10 millimeters long. But these unassuming bristles "really are feathers," he said.
"In terms of the sequence of evolution of feathers, we can now say they start as simple bristles," Benton noted. If this is the case, it would support the idea that the structures that were to become feathers originally developed not for flight but rather for display purposes. "That's a display function," Benton said. "It's clearly not for flight."
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6 Comments
Add CommentOkay, but how were they at, say, POKER?
Reply | Report Abuse | Link to thisI'll bet they cheated!
"a common bacteria" in the article.
Reply | Report Abuse | Link to thisA common mistake; bacteria is plural. It should be "a common bacterium". You wouldn't write "a common dogs" would you?
It's nice to see colored pigmentation in dinosaurs confirmed, if only because it's what one would logically expect.
Reply | Report Abuse | Link to thisPredator/prey gaming is the same whether mammals, fish or dinosaurs are the players. The most efficient tactic for any creature smaller than its predator is simple camouflage--break up the body outline. The same applies to any ambush predator same size or smaller than its prey. Birds seem to have carried their color perception from their dinosaur past, and this implies the hide-and-seek of prey v predator.
However, I would expect that the largest sauropods and other plant eaters (too big to hide, or even need to) were simply elephant-, or whale-, grey. Though the young were probably well-patterned to hide until they were too big to attack. It would be very interesting to see if traces of melanozomes can be detected in those rare fossil dino eggs that still have the embryo preserved inside.
There is also not only inherent pigment but the protein forms of the individual hairs of a feather create colour through diffractive affects of light and transmission so only part of the mystery can be solved. The rainbow affects as well as the apparent colour of a feather might be from selection absorption, transmission and relection along with pigments
Reply | Report Abuse | Link to thisA good article in SciAm several years ago described bird and reptile vision; a wider and smoother spectrum, into near UV, than mammals like us can see. I've wondered if the coloration of bird feathers makes them look different to each other than they do to us --- that might explain the lack of apparent differences (to us) in coloration between the sexes of some species, e.g., penguins. That seems an anomaly considering the dimorphism of most birds.
Reply | Report Abuse | Link to thisSince modern birds and reptiles share that characteristic, one might guess that dinosaurs had it as well. The fossil record might eventually sort that out.
gripping story.....
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