AP BIOLOGY

Detailed explanation-1: -Scientists specifically use index fossils to correlate strata found in different geographic locations. Index fossils are the preserved remains of plants and animals (primarily animals) that have existed in a limited geologic period, making them highly effective in determining the relative age of a rock layer.

Detailed explanation-2: -Fossil species that are used to distinguish one layer from another are called index fossils. Index fossils occur for a limited interval of time. Usually index fossils are fossil organisms that are common, easily identified, and found across a large area.

Detailed explanation-3: -Ammonites, trilobites, and graptolites are often used as index fossils, as are various microfossils, or fossils of microscopic organisms.

Detailed explanation-4: -Shelly fossils, such as brachiopods (lamp shells) and trilobites, have proved most useful for correlation within individual continents because of their tendency…

Detailed explanation-5: -Biostratigraphic correlation uses index fossils to determine strata ages. Index fossils represent assemblages or groups of organisms that were uniquely present during specific intervals of geologic time.