Paleontologists Lida Xing and colleagues announced the discovery of one of the most amazing fossil specimens yet known: a baby bird preserved in a nugget of amber. The amber specimen, about the size of half of an avocado, allows details of the bird's anatomy to be seen in extraordinary detail and in three dimensions, something no other fossil specimen have shown.
Rocks deposited in the middle portion of the Cretaceous Period from Myanmar (formerly called Burma) are famous for their numerous large amber specimens. This amber is important for the gem and jewelry industry, and many scientifically important amber specimens have been discovered in amber markets. Amber is formed when tree sap is buried in sediment. Over millions of years, the sap hardens and can frequently contain parts of plants and insects. On rare occasions, amber can preserve portions of larger animals, as in this case.
The baby bird preserved within the nugget of amber is about the same size as a chickadee, with the head, neck, wings, legs, and tail found within the specimen. The entire body was probably originally trapped in sap, but the torso was lost to decomposition before it was fossilized.