 P-A-L-E-O-Z-O-O-L-O-G-E, Paleozoalogy, also spelled as Paleozoalogy, is the branch of paleontology, Paleo-Bio-Logy, or zoology dealing with the recovery and identification of multicellular animal remains from geological or even archaeological contexts. The use of these fossils in the reconstruction of prehistoric environments and ancient ecosystems. Definitive, macroscopic remains of these metasodons are found in the fossil record from the Ayurvedic Akara period of the Neoprotrozoic era onwards, although they do not become common until the later Ponian period in the latter half of the Paleozoic era. Perhaps the best-known macrophosals group is the dinosaurs. Other popularly known animal-derived macrophosals include trilobites, crustaceans, ikina berms, brachyepods, molluscs, phony fishes, sharks, vertebrate teeth, and shells of numerous invertebrate groups. This is because hard organic parts, such as bones, teeth, and shells resist decay and are the most commonly preserved and found animal fossils. Exclusively soft-bodied animals such as jellyfish, flatworms, nematodes, and insects are consequently rarely fossilized, as these groups do not produce hard organic parts.