Anoxia (ann-ox-ee-uh) Lack of oxygen in the environment.

Arthropod (ar-throw-pod) Jointed leg animal; animal having a chitinous exoskeleton that is usually molted as the animal grows.

Calcite (cal-site) Mineral composed of calcium carbonate.

Chitin (kite-in) Complex polysaccharide (sugar) used by arthropods to construct their external skeletons.

Conchostracan (conch-aa-stra-con) Clam shrimp; small bivalved arthropod.

Concretion (con-cree-shun) Rounded mass of minerals usually developed around a fossil nucleus.

Coprolite (cop-row-lite) Fossilized excrement.

Desiccation (des-ick-kay-shun) The process of drying.

Dissolution (dis-sul-oo-shun) Process of dissolving minerals, rocks, fossils etc.

Elrathia (el-rath-ee-uh) Generic name of a trilobite of Cambrian age.

Eurypterid (yer-ip-ter-id) Sea scorpion; a pincer-bearing Paleozoic arthropod related to horseshoe crabs.

Exoskeleton (ex-oh-skel-uh-ton) External skeleton.

Fossil (fos-sill) Any evidence of ancient life (more than 10,000 years old).

Generic (jen-air-ick) Referring to a genus.

Ichnofossil (ick-no-fos-sill) see trace fossil

Lithification (lith-ih-fih-kay-shun) Process of changing sediment into rock.

Metamorphism (met-uh-morf-ih-zum)  Process of changing rocks through application of heat and pressure.

Ooid (oo-id) Tiny round grains composed of concentric layers around a nucleus, usually calcium carbonate.

Oolite (oo-lite) Sedimentary rock composed of ooids

Paleo- (pay-lee-oh) Prefix; refers to something ancient.

Paleozoic (pal-ee-oh-zoh-ick) Era of geologic time between 543 and 248 million years ago.

Pecopteris (pea-cop-ter-us) Generic name for the leaf of a fern or seed fern of Pennsylvanian age.

Pyrite (pie-right) Mineral composed of iron sulfide.

Silicate (sill-ih-kate) Mineral or rock composed of silicate molecules (silicon and hydrogen).

Strata (strat-uh) Layers of sediment or rock.

Stromatolites (stroh-mat-oh-lite) Horizontal to columnar sedimentary buildup composed of thin alternating layers of sediment and blue-green bacteria.

Trace fossil (trayss fos-sill) Evidence of the activity of an ancient animal (for example, burrow, boring, footprint, coprolite, bite mark).

Trilobite (try-loh-bite) Paleozoic marine arthropod having an exoskeleton composed of calcite and chitin and divided into three longitudinal lobes.

Tullimonstrum (Tull-lee-mon-strum) “ Tully monster;” generic name of a narrow,elongate marine animal of Pennsylvanian age and uncertain affinities.