index fossil

noun

: 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
These examples are automatically compiled from online sources to illustrate current usage. Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Pappas reports that Agnostus is a great index fossil. Jason Daley, Smithsonian, 19 Sep. 2017

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.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/index%20fossil. Accessed 5 Nov. 2024.

Kids Definition

index fossil

noun
: 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

More from Merriam-Webster on index fossil

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!