GEOLOGY

Detailed explanation-1: -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-2: -Index fossils are fossils that are widespread but only existed for a short period of time. Index fossils help scientists to find the relative age of a rock layer and match it up with other rock layers. Living fossils are organisms that haven’t changed much in millions of years and are still alive today.

Detailed explanation-3: -Paleontological resources, or fossils, are any evidence of past life preserved in geologic context. They are a tangible connection to life, landscapes, and climates of the past. They show us how life, landscapes, and climate have changed over time and how living things responded to those changes.

Detailed explanation-4: -Index fossils are the remains of plants and animals that lived for a limited period. Best index fossils are common, widely distributed, and easy to identify. Some of the most common index fossils are ammonites, trilobites, and graptolites.

Detailed explanation-5: -Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time.