Amber is great at preserving insects, although it rarely captures vertebrates. But in 2015, a truly stunning piece of amber turned up in a market in Myanmar, containing a section of a dinosaur's tail, complete with feathers.
A total of eight vertebrae were found inside the amber, surrounded by fluffy feathers and soft tissues. Judging by CT scans, the bones and the feathers were found to be more "primitive" than those of modern birds or their relatives. Scientists were even able to take samples from the tissue where it meets the surface, and determined that it belonged to a small member of the Coelurosaur family. They also found traces of a compound from red blood cells, which you just can't get in dusty old bones.