index fossil


: a fossil usually with a narrow time range and wide spatial distribution that is used in the identification of related geologic formations

Examples of index fossil in a Sentence

Recent Examples on the Web Pappas reports that Agnostus is a great index fossil. Jason Daley, Smithsonian, 19 Sep. 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'index fossil.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1900, in the meaning defined above

Time Traveler
The first known use of index fossil was in 1900

Dictionary Entries Near index fossil

Cite this Entry

“Index fossil.” Dictionary, Merriam-Webster, Accessed 18 Jul. 2024.

Kids Definition

index fossil

: a fossil that is found over a relatively short span of geological time and can be used in dating formations in which it is found

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