Scientists Find An Intact Dinosaur Tail For The First Time And It Is All Covered in Feathers

The tail of a feathered dinosaur has been found perfectly preserved in amber mined in Myanmar.

Scientists discovered a fragment of a 99-million-year-old dinosaur tail preserved in amber. The finding includes bones, tissue, feathers and more, according to a study published in the journal Current Biology.

The piece of amber in which the specimen was found had already been polished for jewelry when scientist Lida Xing, the first author of the study discovered it held a bigger treasure: namely, the first feathered dinosaur appendage ever found. Xing and her team believe the tail comes from a juvenile coelurosaur, a sparrow sized dinosaur.

Upon examination of the specimen, the scientists conluded the tail was chestnut brown on top and white on its underside. Here’s a high-res image of the find (click to enlarge).

Photo: R.C. McKellar, Royal Saskatchewan Museum

The discovery opens a new window on the biology of a group that dominated Earth for more than 160 million years. Although individual feathers stuck in amber have been found from the era of dinosaurs, end their existence is evidenced by fossil impressions, this is the first time scientists have been able to clearly associate well-preserved feathers with a dinosaur, and thus gain a better understanding of how dinosaur feathers, and in turn, feathered dinosaurs, have evolved.

“This is the first time we’ve found dinosaur material preserved in amber,” study co-author Ryan McKellar, of the Royal Saskatchewan Museum in Canada, told BBC News.

A micro-CT scan reveals the delicate feathers that cover the dinosaur tail. Photo: Lida Xing

Xing, a professor at the China University of Geosciences in Beijing, discovered the extraordinary fossil at an amber market in Myitkina, Myanmar.

The amber, some 99 million years old, had already been polished for jewellery when the professor had a closer look at it. The seller had thought it was plant material, but it actually turned out to be the tail of a feathered dinosaur about the size of a sparrow.

By tracking down the amber miner who had originally dug out the specimen, Xing was able to find out where the piece came from.

The feathered, sparrow-sized coelurosaur. Artist’s impression by Cheung Chung-Tat

Examination of the tail’s anatomy showed it definitely belonged to a feathered dinosaur and not an ancient bird.

The feathers lack the well-developed central shaft – a rachis – known from modern birds, McKellar explained. Their structure suggests that barbs and barbules – the two finest tiers of branching in modern feathers – arose before the rachis formed.

The anatomy of the tail confirms it belonged to a feathered dinosaur and not an ancient bird. Image credit: Xing et al.

“We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives,” he added.

“Instead, the tail is long and flexible, with keels of feathers running down each side.”

According to McKellar, there are signs that the dinosaur still contained fluids when it got stuck in the tree resin that eventually formed the amber. When the scientists examined the chemistry of the tail where it was exposed at the surface of the amber, they discovered traces of ferrous iron, an evidence of the blood that was once in the sample.

This raises the probability that the animal could have become trapped in the sticky substance while it was still alive.

Apparently, the dinosaur contained fluids when it was incorporated into the tree resin that eventually formed the amber – this means that the animal could have been alive while becoming trapped in the sticky substance. Image credit: Xing et al.

“It’s amazing to see all the details of a dinosaur tail – the bones, flesh, skin, and feathers – and to imagine how this little fellow got his tail caught in the resin, and then presumably died because he could not wrestle free,” co-author Prof Mike Benton, from the University of Bristol, added.

The discovery also sheds more light on how feathers were arranged on these dinosaurs. When corpses become fossils in sedimentary rocks, 3D features are often lost due to the occurring compression. However, amber is different.

Photo: R.C. McKellar, Royal Saskatchewan Museum

Kachin State, in north-eastern Myanmar, where the specimen was found, has been producing amber for 2,000 years. Because of the large quantity of insects and other animals preserved in the deposits, over the last two decades the place has become a focus for scientists. Unfortunately, however, the larger amber pieces often get broken up during the mining process and turned into things like jewellery.

Hence, scientists hardly come across a complete specimen that would allow them to establish, for example, how feathers were arranged across the whole body, or to look at other soft tissue features that don’t usually get preserved. With other preserved parts of a feathered dinosaur at hand, they would probably also be able to tell whether it was a flying or gliding animal.

“There have been other, anecdotal reports of similar specimens coming from the region. But if they disappear into private collections, then they’re lost to science,” McKellar noted.

Amber mine in Myanmar. Who knows how and where the amber will end up? Photo: Sieghard Ellenberger

While such discoveries are definitely fascinating, it’s important to note the palaeontology community is currently debating whether the scientific information that can be gleaned from these specimens collected and sold in Myanmar is worth the price of the potential human consequences, including the persecution of the Kachin ethnic minority. Amber has driven remarkable discoveries about the prehistoric world, but concerns about its sourcing are growing.

Sources: 1, 2, 3, 4, 5

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