Feathered Dinosaur Tail Found in Asian Amber Market

This photograph shows the tip of a preserved dinosaur tail section, showing carbon film at its surface exposure, and feathers arranged in keels down both sides of tail. Credit: Royal Saskatchewan Museum (RSM/ R.C. McKellar)

(CN) – A piece of amber purchased at a market in Myanmar contains the feathers and partial tail of a baby dinosaur that lived about 99 million years ago, preserved well enough for scientists to fill in details of the dinosaurs’ feather structure and evolution.

Originally advertised as some kind of plant inclusion that could become a piece of jewelry, Lida Xing from the China University of Geosciences recognized its potential scientific importance and encouraged the Dexu Institute of Paleontology to buy it.

After performing CT scans and microscopic observations of the specimen, researchers determined the feathery tail belonged to a dinosaur – not a prehistoric bird.

“The new material preserves a tail consisting of eight vertebrae from a juvenile; these are surrounded by feathers that are preserved in 3-D,” said Ryan McKellar, co-author of findings on the specimen published Thursday in the journal Current Biology.

“We can be sure of the source because the vertebrae are not fused into a rod or pygostyle (a triangular plate that typically supports the tail feathers) as in modern birds and their closest relatives. Instead, the tail is long and flexible, with kneels of feathers running down each side.”

This reconstruction depicts a small coelurosaur approaching a resin-coated branch on the forest floor. Credit: Chung-tat Cheung

The feathers show that the tail had a chestnut-brown upper surface and a pale or white underside, according to the study. The feathers also lack a well-developed central shaft, and their structures suggests that two finest tiers of branching in modern feathers, known as barbs and barbules, arose before a shaft formed.

The authors also noted how amber – which protects encased specimens from chemical alteration by the environment and helps to preserve them in three dimensions – can be a valuable supplement to fossil records.

“Amber pieces preserve tiny snapshots of ancient ecosystems, but they record microscopic details, three-dimensional arrangements, and labile tissues that are difficult to study in other settings,” McKellar said.

“This is a new source of information that is worth researching with intensity and protecting as a fossil resource.”