Index Fossil Lab Name: Index fossils are fossils used to define and identify geologic periods. If geologists find specific fossils in sedimentary rock deposits they are able to estimate how long ago the rocks formed. In this lab you will identify and date fossils using the geologic time scale on the back of this lab. Record the sample number then use the key on the boxes to identify the fossil. Use the geologic time scale to date the fossil. Sample # Species Name Era Analysis: How else can geologists estimate the age of rocks? Period Age Geologic Time Scale Geological Time Scale copyright 2005 - geology.com http://www.geology.com/ http://geology.com/time.htm