Palaeozoology, also spelled as Paleozoology (Greek: παλαιόν, palaeon "old" and ζῷον, zoon "animal"), is the branch of paleontology, paleobiology, or zoology 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 th

Trilobite: Eyewitness to Evolution