Reconstructing the past is a difficult job, whether you’re trying to understand a civilisation that’s long gone, or an ecosystem that vanished before humans ever existed. It’s easy to imagine how things might have looked, but much harder to prove it. Luckily, the journal Nature has brought us some good news on this front. A group of palaeontologists have managed to bring a piece of the past to life, using fossils to reconstruct the colouring of a little dinosaur called Sinosauropteryx.
Think of dinosaurs and you’ll probably conjure up an image from the film Jurassic Park – big, scaly, green animals in a misty jungle. But although we can use fossil evidence to predict dinosaurs’ body shapes and even behaviour, their colours have so far been just guesswork.
Scientists now think that one group of dinosaurs, the theropods, were the ancestors of modern birds. This group includes some of the most famous dinosaur species like Velociraptor and T.Rex, and Sinosauropteryx, the star of this particular particular dramatic reconstruction.
It’s this evolutionary link between birds and dinosaurs that’s given us the chance to find out what Sinosauropteryx looked like – in colour. The new evidence comes not from fossilised dinosaur skin (which is only rarely preserved and then not in its original colours), but from feathers. The new fossils are from an area in northern China that has already proved to be a goldmine for palaeontologists. Other fossils found in this region have suggested, controversially, that some theropods had feathers – and Sinosauropteryx is no exception.
The fossil feathers are so well preserved that the tiny cell structures (melanosomes) that gave them their colour have survived for over 100 million years. And they can now be analysed to work out how the feathers would look if we could go back in time (or do some Jurassic Park-style cloning).
By comparing the shapes of the fossilised melanosomes to those in modern birds’ feathers, the scientists worked out that the turkey-sized Sinosauropteryx had a reddish-brown and white striped tail – perhaps for use in a mating ritual (although here we’re back to guesswork again). And just in case you’re not excited by the fact these scientists have shown us the colours of an animal that went extinct millions of years ago, you’ll be reassured to know they haven’t gone to all this trouble just for our aesthetic appreciation.
This kind of research helps palaeontologists to find out more about exactly how theropods and birds are related, and also to understand how and when feathers first evolved, and what they were for. The researchers argue that the discovery of the melanosomes proves that the fossils are of true feathers, something that hadn’t been certain before. Hopefully further studies will add more detail (and colour) to this picture.
Because science hasn’t given us a time machine yet, fossils are the only clues we have for reconstructing the enormous ‘tree of life’. This particular fossilised piece of the puzzle shows how a lot of luck (thank goodness those feathers made it this far) and skill can give us a colourful glimpse of the past.