Sol definition, the syllable used for the fifth tone of a diatonic scale. See more.
Examples of index fossils. Index fossils (also known as guide fossils, indicator fossils or zone fossils) are fossils used to define and identify geologic periods (or faunal stages).
Click on an underlined word for more information on that subject. If the dinosaur or paleontology term you are looking for is not in the dictionary, please e-mail us. Index fossils are commonly found, widely distributed fossils that are limited in time span. They help in dating other fossils found in the same sedimentary layer. For example, if you find a fossil from an unknown era near a fossil from a known time, you can assume that the two species were from about the same time.