Trending Science: Dinosaur feathers identified in astonishing (and accidental) discovery

The literal gemstone of a find contains a tail sample of around 3.7cm in length, with chestnut-coloured feathers on the top and pale feathers underneath. The amber sample also contained fossilised bones, as well as traces of muscles, ligaments and mummified skin.

Unfortunately researchers say that it’s impossible to determine the exact dinosaur species to which the tail belonged but they do say that the dinosaur lived around 99 million years ago during the Cretaceous period and was most likely a juvenile, non-avian theropod. This was a group of dinosaurs that contained some of the most well-known dinosaurs in popular culture, including Velociraptors and tyrannosaurs. ‘If you were to hold [an adult] in your hand, it would have been about the size of a sparrow,’ commented Ryan McKellar, a co-author of the research from the Royal Saskatchewan Museum, Canada.

The new study that details the discovery, in the journal ‘Current Biology’ also gives a full account of the sample’s amazing and accidental discovery. When found in an amber market in Myitkyina, Myanmar, it was thought to be some sort of plant (perhaps unsurprising considering the fern-like feathers) and was offered for sale for use in jewellery or as a curiosity. Lead author of the study Lida Xing recognised its importance and saved it from becoming a bauble that would remain buried in scientific obscurity.

This fossil suggests that feathered dinosaurs had a much wider variety of feather forms than would be predicted just by looking at modern birds and their development. Airy and flexible, they are more like the ornamental feathers of modern birds than stiff, compact flight feathers. As such, if the whole animal was covered in feathers like these found on its tail, it is very unlikely to have flown.

Certainly the sample is not the first piece of amber found to contain prehistoric feathers. Indeed, the study authors have previously discovered wing tips with skeletal remains from a group of extinct primitive birds called Enantiornithes, as well as a wide array of amber-bound feathers which could not be linked to particular animals. But none have been clearly linked to a non-avian dinosaur before.

‘It is the first time we are seeing skeletal material with feathers coming off the sides of it and we know for sure that we are dealing with something that is not a bird, it is more dinosaur-like,’ McKellar said. The all-important clues lie in the length of the tail, the shape of the vertebrae, and the fact that the vertebrae are not fused into a rod-like structure as they are in birds.

Although they believe the dinosaur could not fly, they do hypothesise that the feathers may have played some kind of role in either camouflage or visual signalling.

Moving forward, McKellar argues that amber offers unique opportunities to capture an accurate glimpse of the past. ‘I think the most exciting aspect is how much amber can add to vertebrae palaeontology,’ he said. ‘Even a few small scraps like this, they give you a quality of view where the preservation is so good that you can start to answer the bigger questions, even though you are not necessarily getting the whole animal.’