National Geographic should have a 3-D animation up soon
The pursuit of accurate dinosaur colours just turned into a race, and a heated one at that. Just last week, I wrote about a group of scientists who claimed to have accurately identified the colours of some feathered dinosaurs by microscopically analysing three fossils. According to that study, Sinosauropteryx had a tail covered in ginger stripes. Now, another group have revealed the palette of an entire dinosaur, Anchiornis. This tiny predator had a dark grey body and the limbs bore long, white feathers tipped with black spangles. Its head was mostly grey with reddish-orange and black specks, and an extravagant reddish-orange crown.
Both reconstructions are based on microscopic structures called melanosomes. They're partly responsible for the brilliant colours of modern bird feathers, they're packed with pigments, and they happen to fossilise well. There are two major types. Spherical 'phaemelanosomes' contain a reddish-brown or yellow pigment while the rod-like 'eumelanosomes' have black-grey tints.
The technique of inferring colours from fossil melanosomes was pioneered by Jakob Vinther at Yale University. He used it to show that a Cretaceous bird feather probably had black and white stripes and, later, that another fossil feather had an iridescent starling-like sheen. But these were analyses of single papers and even last week's paper coloured Sinosauropteryx by looking at just one part of a single individual.
Vinther isn't impressed with his rivals. "They are in the Stone Age when it comes to understanding melanosome fossilization and interpretation of original colors," he says. To him, it's simply not enough predict colours based on the presence of one type of melanosome. Even the hues of single feathers can depend on a mix of the two melanosome types with different concentrations of pigments. So you need to know the distribution of melanosomes across an animal and even then, you still need to work out how that translates to different colours.
And that's exactly what he's done. When I spoke to Vinther last week, he said, "We are still far from putting colours on dinosaurs [but] the future is promising. Eventually we will have dinosaurs in technicolour. We are working seriously on that currently." He wasn't kidding!
He had been working on a new specimen of Anchiornis with the catchy name of BMNHC PH828. The tail is missing but the rest of the skeleton is beautifully preserved, including the skull and both sets of limbs with their elegant plumes. Rather than looking at individual body parts, Vinther took 29 samples from the specimen, representing every type of feather types across different body parts. In each one, he thoroughly analysed the size, shape, density and distribution of melanosomes.
To interpret this goldmine of data, he worked with his colleague Matt Shawkey to catalogue the melanosomes from a wide variety of living birds, from ravens to finches to mallards. This modern data set was a cross between a paint catalogue and a Rosetta stone. It told Vinther how different combinations of melanosomes led to different colours and allowed him to correctly paint his Anchiornis.
The animal was a tiny hunter just 13 inches in length. Its name, appropriately enough, means "near bird". It was mostly black and grey, for an electron microscope revealed melanosomes in all 29 samples from all over its body.
Like the related Microraptor, Anchiornis had four wings, with long flight feathers on both its arms and legs. These feathers had very few melanosomes at their bases, suggesting that they were white or very lightly pigmented. Reddish-brown phaeomelanosomes only turned up in the dinosaur's crown feathers, and in patches on the side of its skull, interspersed with eumelanosomes. Anchiornis would have looked like it was wearing an orange hat and ginger freckles.
Many of these colours should be familiar to modern bird-lovers. The orange crest recalls the headdresses of quails and tinamous, while the spangled wings are similar to those of domestic chickens. Modern birds used these complex colours to communicate with peers, display to mates or posture to predators. To Vinther, this suggests that the early evolution of feathers was shaped by the desire to talk to others as much as the need to be aerodynamic.
Even this analysis may not paint a completely accurate picture of Anchiornis. As Vinther admits, some pigments like the orange-yellow carotenoids or the greenish-purple porphyrins affect bird colours but haven't been considered. Nonetheless, these pigments are rare, even in modern birds. "I think it is unlikely but of course not impossible that Anchiornis had some of these pigments," says Vinther. "In fact, carotenoids get fossilized, we can recognize them as chemical traces, but we have focused on the shape of melanosomes and not the chemistry."
For the moment, Vinther has plans to produce colour schemes for other dinosaurs, although the competition certainly makes things more difficult. "We did have a hard time getting access to material in China because of the competing group," he says, "but [our collaborators] Li Quanguo and Gao Ke-Qin have more specimens at the Beijing Natural history museum that we will study."
Reference: Li et al. 2010. Plumage Color Patterns of an Extinct Dinosaur. Science http://dx.doi.org/10.1126/science.1186290
More on feathered dinosaurs:
- What colours were dinosaur feathers?
- Evidence that Velociraptor had feathers
- Beipaiosaurus was covered in the simplest known feathers
- Tianyulong - a fuzzy dinosaur that makes the origin of feathers fuzzier
- Microraptor - the dinosaur that flew like a biplane
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Being able to tell what colors dinosaurs actually were? What's not to love? I may have a smile all day thinking about this. I wonder how long it will take for museums to start incorporating the correct colors into their displays.
Is it possible we're trying a wee bit too hard to make them look like something we can a) identify with in terms of today's birds and b) love? Let's not make them 'cute'.
Cute? Hell, if anything, my mind would like nothing better than to resist the coloured feather-isation of raptors and get back to the more reptilian version with the zombie-hands, but if that's what they were like, that's what they were like.
It's getting more interesting every week! But I still wonder, what did these animals smell like? :-)
Rhode Island Reds, the Jungle Fowl, Sinosauropteryx, Anchiornis, I'm suspecting there is something meaningfully special about the colors such as chestnut, orange-brown and similar, and the suspicion starts not from me but from a perception by a language. Surprisingly to me, "fauve" in French means "wild" but surprisingly it is also a color. Lions, tigers, chipmunks, all similar are colored "fauve." No I don't know what the special meaning would be for the fauve colored animals.
@david (#5), I believe that translates as "tawny".
Nice reconstruction -- is there a reason for the naked snout, though?
No, that's what they looked like. The resistance to the idea that non-avian dinosaurs (even the ones that are most closely related to birds) could look like birds has been oddly intense.
@ Mike Keesey
The new specimen seems to have less extensive snout feathers than the last but it looks like it's incompletely preserved. So the snout should probably be mostly if not completely feathered. \
Anyway, this is beyond cool. I just wish the paper had gone into more detail on the structure of the feathers in this new specimen as well. It seems to imply that all the contour and crown feathers are pennaceous, and it certainly looks like there are pennaceous crown feathers in the photos. However the last Anchiornis paper implied those were all plumaceous. Could the apparently widespread plumaceous contour feathers (in e.g. Sinornithosaurus) just be taphonomic?
I find this very cool as science. But my reaction to the picture above was a disappointed, "that looks like a bird, not a dinosaur." How long do you think it will take before generations of kids grow up picturing dinosaurs with feathers? And will those generations of kids be less excited by dinosaurs than they are now? Or will they all become avid bird watchers as adults?
It's worth reminding ourselves that Anchiornis isn't exactly representative of the entire order. It was tiny and had long feathers that were flight-capable (or thereabouts). And, in fact, feathers or dinofuzz have only been clearly demonstrated in a minority of species (25 according to Wikipedia).
Put it this way - for the foreseeable future, Stegosaurus will still look like Stegosaurus, Triceratops will still look like Triceratops, and the giant carnivores will still capture the imaginations of children for generations to come.
That's fascinating. I'm frantically busy writing the 9th (and I hope final) draft of my current book, but I enjoyed reading this and emailed the link to my older dtr (11).
@ Mike Keesey # 6
Not so fast. Colors do not translate well. The tawny translation is only for when you talk of a person's skin. The translation color for like "on your wall" would be faun, which still leaves a lot to be desired because some have more red-orange, others less. Even within English, color names can be difficult to give in words from one person to another.
I very much want to see the next dinosaur movie feature at least a few of the feathered and coloured dinosaurs, or showing them with dinofuzz.
Spectacular! And as one of those kids who grew up with a more modern interpretation of dinosaurs (first as bird-relatives, then with feathers) it does nothing to diminish their coolness. If anything, it makes them cooler. No longer do I have to go "I wish there were still dinosaurs around". Now I have the satisfaction of looking at my pet parrot and imagining what once was.
A lovely sentiment.
1) Do we know more about dino skin colour, or is it feather-only for now?
2) Is there a possibility that some additional pigments have not been preserved as well as the others? Not sure how you could test that, perhaps checking if there are clear, slow, linear (or at least monotonic) downwards trends in the concentration of different pigments across lineages...
I have to say that, as a lifelong amateur of things dinosaurian, I wearied of the emphasis generally placed on the giant carnivores and their presumed giant prey while still a child. I couldn't believe that the mesozoic was all like that - after all those things really were dumb and clumsy, there was only so much you could say about them, and I resented the fact that the under-fauna never got properly covered in kids' books. I wonder if the pendulum in the popular press has swung too far the other way now.
Yes! I love the idea of multicoloured dinosaurs, I was always so disappointed at school by the portrayal of them as brown/green creatures. Animals today have such a wide variety of colours, no reason why the dinosaurs shouldn't have.
@Toto: I think dinosaur skin is still very much an open question. They were coloured green and brown originally because it 'made sense' in terms of camouflage. Which always puts into my mind a hilarious image of a Brachiosaurus (or whatever their called now) trying to hide behind a tree.
Melasomes, which were studied here to give Sinosauropteryx and Anchiornis their colors, is unique to bird feathers, so no dinosaur skin colors yet.
Elizabeth, the only really avian dinosaurs were maniraptors, a good-sized group of carnivorous dinosaurs that includes raptors, troodontids (like Anchiornis here), and oviraptors (among others). AFAIK, there isn't good evidence for actual feathers among other theropods. There's fuzz, though, in more basal coelurosaurs like compsognathids and tyrannosauroids.
Slightly off-topic: I love feathered dinos more than I love Satan, which is saying something. Some dinosaurs in that line had reduced or lost feathers secondarily. I could use some clarification on those. Is there any evidence - other than conjecture - that large species like T. rex had lost their dino-fuzz? I understand large, heavy-set species of mammal convergently lose hair, so one could guess the same of T. rex, but what evidence is there? Then the other oddball - pelecanimimus. I have a hypothesis and tell me if it's wrong: The famous skin impression of that beast had lost its feathers in decomposition a la the "Montauk Monster."
Then if a feathered dino goes featherless, what replaces that? Smooth skin or scales? The genes for scales are still present we see them on bird feet - but partially bald birds like vultures don't have scales on their faces, as far as I know.
Back to color - If the melanosomes in question are only found in feathers, what gives color to the scaly parts of birds, or bare skin (turkey heads are quite colorful)? Could we find evidence for color there, or are we just boned?
Apologies for any misspellings and stupid mistakes there - got my dino knowledge from he University of Dougal Dixon...
@Wim (#4) How did they smell? How about, how did they taste?
@27, If it looks like a chicken, don't be too surprised if it tastes like one...
@7 I'm not resistant to them having feathers -- just the idea that we want to make them 'cute' or recognizable in order to appreciate them. They were pretty cool when they were . . . um . . . NOT cute.
It's actually kind of cool that with colored feathers the dinos will look more like the way the preschoolers color them...of course, in Sunday School last week they gave Noah blue skin, so . . . (it's a joke people)
It seems rather silly to have portrayed two-ton monsters that you could hear coming from a mile away in "camouflage" colors of mixed grays, greens and browns. Yes, that would really make them near invisible!
Regarding birds' wing colors -- I wish I could remember where, but I read in a neurology text (a section on perception) that some bird feathers do not actually have the pigment that we perceive as a particular color, but that their feathers are formed in a way that reflects a particular band of light, so we see the particular color associated with the wavelength being reflected. I wonder if dinosaurs had this sort of structure in their feathers (or skin?). That would certainly complicate matters.
Don't forget though that colour has many functions besides camouflage - communication, species recognition, sexual selection, signalling fitness... There's no reason to think that the giants weren't brightly coloured too in some ways.
Oh and you're talking about structural colours. Google that, or iridescence. You can see it in starlings and some butterflies. Whenever an animal looks one colour from one angle and another colour from another angle, chances are you're dealing with structural colours. And yep, Vinther found these in fossil feathers too. If you look at the previous coloured dinos post, you'll find links in the final paras and some discussion in the comments
http://www.skrewtips.com/img/man-with-blue-skin-from-mercola-website.jpg approves their color choice.
Zephyr, here's a nice video explaining structural colours in butterflies.
What do birds smell like?
@ C S Shelton:
Is there any evidence - other than conjecture - that large species like T. rex had lost their dino-fuzz? I understand large, heavy-set species of mammal convergently lose hair, so one could guess the same of T. rex, but what evidence is there?
Skin impressions. Scaly skin impressions. Known from Tyrannosaurus and Albertosaurus, and also for non-tyrannosaurids such as Allosaurus and Carnotaurus.
In regards to your other feather questions, check out Jura's awesome post, here:
Thanks! A lot of relevant info in one place. I'm not convinced by jura's argument that setae are a good argument against fuzz = warm blood. In fact, I find the evidence crocodilians are secondarily cold blooded pretty compelling, which would mean all dinosaurs probably started warm blooded. On the other hand, modern crocodilians are a good case that many dino groups could have reverted to cold blood, but it seems silly to even entertain that possibility for theropods.
And since we know tyrannosaurs started fuzzy and re-acquired scales over the body, that seems to answer my question about whether it's possible for birds to re-acquire scales. My question then becomes Why haven't they? Why do these large ratites not have scales much above the foot area? Wouldn't a scaly ostrich have any survival advantage? I'd think so.
It makes me want to go farther than Ostrom's Chickensaurus and make a scaly chicken.
Great post Ed! My wife may be looking at this one with her grade 1 & 2 class today!