|Branches of Zoology|
Paleozoology (Greek: paleon = old and zoon = animal) is the branch of paleontology (or paleobiology) dealing with the recovery and identification of multicellular animal remains from geological (or even archeological) contexts, and the use of these fossils in the reconstruction of prehistoric environments and ancient ecosystems.
Definitive, macroscopic remains of these metazoans are found in the fossil record from the Ediacaran period of the Neoproterozoic era onwards, although they do not become common until the Late Devonian period in the latter half of the Paleozoic era.
Vertebrate teeth, invertebrate shells and other hard organic parts are the most commonly preserved and found animal fossils. Exclusively soft-bodied animals -- such as jellyfish, flatworms, nematodes, and insects -- are consequently rarely fossilized.