index fossil


Definition of 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, "Look Into the Creepy-Cute Eyes of This Reconstructed, 500-Million-Year-Old Creature," 19 Sep. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'index fossil.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of index fossil

1900, in the meaning defined above

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The first known use of index fossil was in 1900

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Cite this Entry

“Index fossil.” Dictionary, Merriam-Webster, Accessed 20 Jan. 2021.

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