1.) The organisms that became index fossils were found in very large quantities, meaning these organisms we're at one time 2.) What rock made of sediment that become cemented together

3.) What small fossil is only visible with a microscope

4.) Organisms that became index fossils were , holding up well over a long period of time

5.) Most rock that contains fossils were formed in the

6.) Fossils that help determine the age of fossils and rock found in the same sedimentary lager are .