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The fossil remains of an organism that lived in a particular geologic age, used to identify or date the rock or rock layer in which it is found. Also called guide fossil.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
(Geological Science) a fossil species that characterizes and is used to delimit a geological zone. Also called: zone fossil
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
a widely distributed fossil, of narrow range in time, regarded as characteristic of a given geological formation and used esp. in determining the age of related formations.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
index fossil- One useful for dating and demonstrating the relation between strata in which it is found.
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|Noun||1.||index fossil - a fossil known to have lived in a particular geologic age that can be used to date the rock layer in which it is found|
fossil - the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil
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