When Dinosaurs Came in Color

Scientists already knew that birds are descended from the dinosaurs. Now new research says that feathered dinosaurs also had surprisingly colorful plumage

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Clarke et al

An analysis shows that feathered-covered dinosaurs came in different colors

It’s probably hard to believe, but there was a time, not that long ago, when scientists thought dinosaurs were extinct. No, seriously! That was before paleontologists began to understand the impressive anatomical similarities between fossil dinos and living birds. The icing on the cake: a series of discoveries, starting in the 1990s, showing that some dinosaurs even sported feathers. It’s no longer even slightly controversial to claim that birds are descended from dinosaurs, and even that they are dinosaurs—the only branch of the family that survived a massive comet strike 65 million years ago.

With that relationship firmly established, scientists have moved on to looking at some more finely grained questions, and a new paper in Nature is casting light on one of them: since the feathers of modern birds are often intensely colorful, how much color did their extinct cousins display? The answer, it turns out, is probably a lot. Feathers, says Julia Clarke, of the University of Texas, Austin, one of the paper’s co-authors, were brightly colored from the time they first appeared in Maniraptoran dinosaurs, including oviraptors and dromaeosaurs.

(MORE: Birds and Dinosaurs: Their Strangest Feature)

But that’s only part of the story: the genes that control the colors of skin, hair and feathers are part of the body’s melanocortin system, which also influences metabolism, inflammation and sexual function. “We hypothesize,” says Clarke, “that what we’re seeing is a big physiological shift in dinosaurs, a change that has other implications than just the color of feathers.”

What Clarke and her colleagues are actually seeing is melanosomes, structures so tiny they can only be viewed with a scanning electron microscope. “They’re pushed into developing hair or skin,” Clarke says, “and we know that the shapes of melanosomes are related to the chemistry of pigment.”

If an individual’s melanosomes are round, he or she will tend to have red hair or red feathers; if they’re long and skinny, the color is black. Mixes of different-shaped melanosomes are associated with all the colors sported by birds or humans or other mammals. Turtles and lizards, by contrast, don’t show much melanosome variety, and their colors tend to be drab.

Melanosomes can be identified in fossils as well, and when Clarke and her colleagues looked at long-dead dinosaurs and pterosaurs (extinct flying reptiles that weren’t technically dinosaurs), they found a rich diversity of melanosomes in dinosaurs with true feathers, but not in species with the fuzzy filaments that preceded feathers. They don’t know exactly what the colors were, but that answer should come with more research.

They also can’t say why the changeover happened, says Clarke. “When you’re looking back 150 million years through a dirty lens, causality can be hard to get at. We’ve got a lot more to figure out.” But it does seem clear that bright coloration may have been a side effect of a major change in dinosaur metabolism—a change that ultimately allowed one branch of the dinosaur family to escape the bounds of gravity and take to the air.

(MORE: Second Gunman in Death of the Dinosaurs)

3 comments
BabuG.Ranganathan
BabuG.Ranganathan

TALES OF FISH LEGS AND DINOSAUR FEATHERS

By Babu G. Ranganathan

There's been much misinformation in the media recenlty about fish having genes for legs and limbs. This is a total misrepresentation. Fish do not and did not have genes for limbs. They have certain similar regulatory genes as animals with limbs, yes. Regulatory genes regulate and control other genes. In the case of animals with limbs, regulatory genes regulate and control genes for limbs, and in fish they regulate and control genes for fins. This doesn't mean fish have or had genes for limbs!

Recent news reports that scientists have discovered that some snippets of DNA from a fish, they once thought was extinct, can cause mice to grow limbs. This is wrongly being interpreted and hailed by the mass media as evidence that fish evolved legs. Isn't it very interesting that the fish they got the DNA from doesn't have any legs?

These snippets of DNA from the fish seem to be "triggering" mechanisms. They can only trigger ("turn on") formation of limbs if the genes for limbs first exist, and since genes for limbs exist in mice then these triggering mechanisms, even if from a fish, will work. None of this means fish evolved legs.

Imagine an evolving fish having part fins and part feet, with the fins evolving into feet. Where's the survival advantage? It can't use either fins or feet efficiently. There are absolutely no fossils of fish with part fins, part feet to support that any fish evolved limbs. These fish exist only on automobile bumper stickers!

All real evolution and adaptations in nature are within limits. The genes already exist in all species for micro-evolution (variations within a biological kind such as varieties of dogs, cats, horses, cows, etc.), but not for macro-evolution (variations across biological kinds such as from sea sponge to human). The unthinking environment has no ability to design or program entirely new genes. Only variations of already existing genes and traits are possible. A dog will always be a dog no matter how many varieties come into being.

Evolutionists hope and assume that, over millions of years, random mutations (accidental changes) in the genetic code caused by radiation from the environment will produce entirely new genes for entirely new traits in species for natural selection to use, so that macro-evolution occurs. It’s much like hoping that, if given enough time, randomly changing the sequence of letters in a cook book will turn the book into a romance novel, or a book on astronomy!

A major problem for macro-evolution is the issue of survival of the fittest. How can a partially evolved species be fit for survival? A partially evolved trait or organ that is not complete and fully functioning from the start will be a liability to a species, not a survival asset. Plants and animals in the process of Darwinian macro-evolution would be unfit for survival. For example, For example, "if a leg of a reptile were to evolve into a wing of a bird, it would become a bad leg long before it became a good wing" (Dr. Walt Brown, scientist and creationist).

Recently, it was thought they had discovered fossils of dinosaurs with feathers until they found out that many of the so-called feathers were actually scales. The scales took upon a feather-like appearance during the fossilization process. There’s strong evidence that other structures interpreted as feathers are woolly plumages and collagen fibers. A few evolutionists (not even most) interpret these structures as proto-feathers and have artists drawing dinosaurs with fancy feathers for magazines and newspapers!

What about natural selection? Natural selection doesn't produce biological traits or variations. It can only “select” from biological variations that are possible and which have survival value. The real issue is what biological variations and traits are possible in species, not natural selection.

Genetic and biological similarities between species are no proof of common ancestry. Such similarities are better and more logically explained due to a common Genetic Engineer or Designer (yes, God) who designed similar functions for similar purposes in various species. Genetic information, like other forms of information, cannot arise by chance, so it's more rational to believe that DNA or genetic similarities between species are due to intelligent design.

What about "Junk" DNA? The latest science shows that "Junk DNA" isn't junk after all! It's we who were ignorant of how useful these segments of DNA really are. Recent scientific research published in scientific journals such as Nature and RNA has revealed that the "non-coding" segments of DNA are essential in regulating gene expression (i.e. how, when, and where genes are expressed in the body).

All the fossils that have been used to support human evolution have ultimately been found to be either hoaxes, non-human, or human, but not human and non-human.

All species in the fossil record and living are found complete, fully formed, and fully functional. There are no partially evolved species anywhere! There is no macro-evolution in nature.

Visit my popular Internet site, THE SCIENCE SUPPORTING CREATION

Sincerely,

Babu G. Ranganathan*

(B.A. theology/biology)

Author of the popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS

*I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I've been privileged to be recognized in the 24th edition of Marquis "Who's Who in The East" for my writings on religion and science.

arachnophilia
arachnophilia

@BabuG.Ranganathan> For example, "if a leg of a reptile were to evolve into a wing of a bird, it would become a bad leg long before it became a good wing" (Dr. Walt Brown, scientist and creationist).

in the early triassic, a group of arcosaurs got up off their splayed reptilian legs, and placed their legs directly under their bodies. this allowed them a greater range and speed of movement, probably because they were now warm blooded and no longer needed to hug the ground for warmth. supporting legs were better than splayed ones. this then allowed them to begin shifting their centers of balance backwards, taking the weigh off their front legs. marginal grasping ability was better than no grasping ability: a better leg. this, combined with the reorganization of respiratory mechanics so that they worked with locomotion, instead of against it, allowed this group of archosaurs, the dinosaurs, to take over as the dominant form of life on the planet.

highly specialized predatory dinosaurs, the theropods, slowly developed more flexible hands, better capable of hunting and grasping prey, including the ability to rotate their wrists in ways other dinosaurs could not. these theropods, the maniraptors, had a better leg than other dinosaurs. they also had feathers. we have found oviraptors sitting on their nests like chickens, with their arms -- which we know from fossils were feathered -- draped over their eggs, keeping them warm. the feathered arm was a better leg than the unfeathered ones.

in the jurassic, an even more highly specialized group of maniraptors found another use for their grasping, rotating hands that sported long feathers. they could use them to generate lift. though the earliest of these, the first birds, and the closely related non-avian dinosaurs, weren't capable of very good flight, the wing that got them away from bigger predators, or closer to their prey was a better leg than the one that didn't.

and from there, it's just a matter of enlarging the furcula (wishbone) and fusing the carpals and metacarpals of the hand together into a carpometacarpus. in fact, at least one bird today, the hoatzin, is born with a fully developed theropod hand with distinct digits, which fuse later in life.

> Recently, it was thought they had discovered fossils of dinosaurs with feathers until they found out that many of the so-called feathers were actually scales.

the really weird part? scales in birds (foot scutes) are TURNED ON by regulatory genes. impede those, and they grow feathers on their feet. go back in the fossil record, and some of the earliest birds and closely related non-avian dinosaurs (eg: microraptor) have feathers on their feet.

> The scales took upon a feather-like appearance during the fossilization process.

these are scales?

http://i.imgur.com/JiXQsMM.jpg
 
granted, the picture is bad here, but on the actual fossils (there are 6 complete specimens) you can see the veins, barbs, etc: they're essentially modern, asymmetrical flight feathers. on a dinosaur, with a long bony tail, teeth, unfused carpals/metacarpals, unopposed hallux, unfused dinosaurian hip, and without a prominent breastbone "keel".

creationists like to call this a bird (and indeed, most scientists call it the first bird), but it is a mistake to stop there. it is undoubtedly a dinosaur. side-by-side with other maniraptors, like velociraptor, the similarity is staggering. it even has the hyperextensible second digit on the foot, the hallmark of dromaeusaurs. and we know now that velociraptor had wings as well, as we have found quill barbs on its forearms.

> There’s strong evidence that other structures interpreted as feathers are woolly plumages and collagen fibers.

and feathers are?

> A few evolutionists (not even most) interpret these structures as proto-feathers and have artists drawing dinosaurs with fancy feathers for magazines and newspapers!

the dinosaur i showed above is archaeopteryx lithographica. the "lithograph" part of it's name comes from the fact the feathers are so well preserved, it was as if it were a lithograph in a textbook. it is not a matter of drawing; those are feathers.

> Genetic and biological similarities between species are no proof of common ancestry.

and paternity tests don't work either, right? genetic similarity IS proof of common ancestry; that's how genes work.

> Such similarities are better and more logically explained due to a common Genetic Engineer or Designer (yes, God)

okay. why would a "common genetic designer" give us genetic evidence of primate chromosomes fusing in humans, such that one human chromosome not only matches two chimpanzee chromosomes, but the human one contains two ending telomeres in the center? seems like a funny design. also, while we're at it, why would a "common genetic designer" cause ERVs to appears at distinct points, and then be passed down to all similar designs? seems like a mistake he could have fixed.

> All the fossils that have been used to support human evolution have ultimately been found to be either hoaxes, non-human, or human, but not human and non-human.

phylogeny challenge time again:

http://i.imgur.com/FW1SNMN.jpg

which ones are human and which ones are non-human? hint A=chimpanzee, N=homo sapien.

arachnophilia
arachnophilia

@BabuG.Ranganathan

> Imagine an evolving fish having part fins and part feet, with the fins evolving into feet. Where's the survival advantage? It can't use either fins or feet efficiently.

this is a fundamental misunderstanding of evolution, which is not necessarily about finding the best design right away. it is about marginal improvements becoming inherited in a population. in this case, rigid fins are an excellent adaptation for fish that live near the ocean floor, or for fish that sometimes find themselves in shallow water. and we do not need to imagine it, because:

> There are absolutely no fossils of fish with part fins, part feet to support that any fish evolved limbs. These fish exist only on automobile bumper stickers!

this is either an outright lie, or ignorance your part. indeed we do not even need to look to the fossil record: there are LIVING sarcoperygids (lobe-finned fish). they include the coelacanth and lungfishes, which both have extended bony structures in their fins, unlike actinopterygid (ray-finned) fish which lack those structures, and cartilaginous fishes (sharks) or jawless fishes.

turning to the fossil record, the transition is extremely well demonstrated: http://i.imgur.com/7Tyfb8j.jpg

this image includes a half dozen animals with "part fin, part feet" appendages, which appear in order in the fossil record. in fact, the most recently discovered example among these, tiktaalik, was discovered specifically because of the order. paleontologists knew where to look: in exposed rock of a certain age and certain kind of formation. this is extremely strong confirmation of the idea.

> All real evolution and adaptations in nature are within limits.

the limit is, in fact, generational. each plant, animal, fungi, protist, etc, produces offspring that are basically identical to itself, with minor variation. the problem is that you are proposing some kind of artificial limit to the heritability of those variations. and THAT is nonsense. there is no such mechanism, and creationists have never been able to even propose what such a mechanism would look like. to see the problem here, simply look at any two "transitional" species and try to determine if they are the same kind. aronra called this the "phylogeny challenge" and i invite you to play: http://youtu.be/_r0zpk0lPFU?t=8m40s

note that this video is on the same two topics you mention here.


> The unthinking environment has no ability to design or program entirely new genes. Only variations of already existing genes and traits are possible.

again, this is a fundamental misunderstanding. evolution is essentially two processes: random mutation, and natural selection. the only "design" or "program" happening is the selection, and the "new" genes are mutations of already existing genes. and the selection happens according to factors dictated by the environment. it is no surprise than things come out looking like what the environment selects for.

> Evolutionists hope and assume that, over millions of years, random mutations (accidental changes) in the genetic code caused by radiation from the environment

that is not what causes mutations, unless we're reading marvel comics.