This is a petrified chick about to hatch. The whole fossil was covered with baby Dino Do-do. As I began cleaning, I could smell wet feathers. When I realized what I had, I stopped! It is 1.5″ x 1″ x 1.5″ small, actually. Lined up with the others, you can see how this kind of bird develops. These are in my third Article, The Embryonic Development of Birds.