بیوزون

thumb|upright=1.2|Biozone types. Each rectangle represents bodies of sedimentary rocks and each line a different taxon. The arrows indicate the taxon first or last appearance. In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa, as opposed to a lithostratigraphic unit which is defined by the lithological properties of the surrounding rock.