A zoolite is the fossil of an animal. Here's one of the most famous zoolites:
Archaeopteryx at the Museum für Naturkunde in Berlin - it's still very dinosaur-like, but it already has feathers and is often considered the ancestor of modern birds
Kentrosaurus aethiopicus, also in Berlin
Deinotherium at the Museum am Löwentor, Stuttgart
Stenopterygius quadriscissus, also in Stuttgart. The animal died while or shortly before giving birth. If you looks closely (and click the photo for the big version), you can see three babies inside her, the one clearly visible was probably pushed out of her body when her body decayed.
See what else Z stands for with ABC Wednesday