Among the near interminable questions one has to answer as a palaeontologist such as ‘what was the biggest dinosaur?’ and ‘how fast were they?’ is ‘what colour were they?’. The stock answer is always, ‘well we don’t know, but we can make an educated guess based on living animals’. The new answer is ‘we look at the microstructure of the melanosomes in the feathers’.
Two different kinds of melanosomes from fossil feathers. Modified from Zhang et al., 2010.
Yes, a new paper in Nature today reveals how we might yet be able to work out the colours of some dinosaurs and birds thank to the quite incredible preservation of various animals in places like Liaoning. Melanosomes are tiny organelles that hold colour pigments and help give feathers their colours (more on them here, something written for this paper) and these have now been found in some feathers from ancient fossil beds. For a start this is likely to be the final nail in the coffin that some feathers are just collagen fibers or even fakes as some have claimed, since you know, having a microstructure identical to that seen in modern feathers seems rather unlikely that something 0.005 of a millimetre could be faked.
More importantly and excitingly though, some melanosomes in extant birds vary in size and shape according to the pigments they house. In other words, you can tell what colour they are by their shape. If it’s one shape it’ll be one colour, a different shape, a different colour. That means that if you have a feather from a dinosaur say, you can tell what colour it was by the shape of the preserved melanosomes.
While some fossil feathers already show a striping pattern of light and dark this only tells us that one part was lighter than the other, the actual colours were unknown so it could have been blue and yellow or green and brown or even black and white. The presence of identifiable melanosomes with known structures can help to work out the colours of the animals that bore them. Similar work has admittedly already been done by another research team on feathers of similar antiquity, but this is the first time it’s been applied to dinosaurs.
Inevitably the results are not going to be that dramatic. Only a small part of some individual feathers have been analysed and feather colour is made up of more than just the melanosomes. Nevertheless, some distinctions can be made and the authors note that it looks like Sinosauropteryx for example had a red-brown tail (or at least some russet tail feathers). It’s in one sense a small step forwards, but in the long term it could be one of the most important for finally revealing the colour of the dinosaurs.
Zhang, F. et al. 2010. Fossilised melanosomes and the colour of Cretaceous dinosaurs and birds. Nature. doi:10.1038/nature08740doi:10.1038/nature08740
Share this Post
Holy crap! I’m just speechless. It just comes to show you that we never know what we’ll find. A few decades ago such a discovery would probably have been thought impossible.
Although it has always confused me, you also have the fact that the various blue birds do not have blue feathers. They just look blue. I am not sure how you account for effects that are not a direct effect of the underlying pigment.
Well there are structural changes too. Get a plastic ruler and bend it and you’ll see a variety of colours as the crystals inside move and refract light in different ways.
Russell,
AFAIK, it’s not that birds don’t have blue feathers, but they don’t have blue pigment. The blue color is caused by refraction of light due to the microstructure of the feathers. Presumably this could also be detected in fossils.
And I quote my old textbook:
“We’ll never know what color dinosaurs were. Pigmentation does not fossilize.” In lack of a better word: LOL.
But can the pigment be preserved? I would believe there are areas on this planet that did not offer the proper environment conditions needed at the time for such process to occur. Thus causing the pigmentation to stain or adhere itself to the elements that compose a creature’s final resting spot. Small amounts of remaining moisture could have provided an opportunity for a rare type of mold or a fungus to settle.This having influence over a unique series of events resulting color preservation.
Just a thought. We don’t know much about our planet.
Could happen, I think yes. Did happen and we will find – who knows? I believe there are original pigments preserved for some things in the Messel beds and well, those are *really* old, so if they survived I don’t think it’s impossible that something of the time of the dinos could.
It made the front page of our newspaper (News and Observer, Raleigh, NC, USA). My 6 year old was pretty happy about that. They had a nice picture (January 2010 rendering by artist Jim Robins, provided by the University of Bristol) as well.
Colour me gobsmacked.
Never knowing dinosaur colour has been the mantra for so long it feels like heresy that they’ve achieved this.
I’m also happy this has confirmed the structures as feathers.