While most paleontologists dig up prehistoric bones from the ground, Lida Xing hunts for fossils in the amber markets of Myanmar. In 2015, he made a remarkable find: Trapped in what looked like golden glass was the feathered tail of a dinosaur.

Along with the primitive plumage, the 99-million-year-old amber also preserved soft tissue and eight complete vertebrae. The tail bones indicated that the specimen belonged to a dinosaur that was not a prehistoric bird and also provided researchers with insight into the evolution of feathers.

“This is the first time that skeletal material from a dinosaur has been found in amber,” Dr. Xing, who is a paleontologist at China University of Geosciences in Beijing, said in an email. He and his colleagues published their findings Thursday in the journal Current Biology.