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The Geologic Time Scale: The Development of Life through time
This text assists in understanding time relationships and how life on Earth has changed over time. The dates shown were compiled from several available sources. The first page shows some important events in Earth history, presented in the order in which they occurred. The data are also shown on the scale of a calendar year. On the second sheet is a chart showing the geologic eras, systems, and series. On the chart, each dot, number, or letter represents 1 million years. The dots get older as you read down the chart, or to the right along a row. They represent millions of years before present (mybp) and show the ages of the oldest known fossils of selected animals or the time of an event. Not all of the items are shown on the chart because of space limitations.
Intended for grade levels:
  • Middle (6-8)
  • High (9-12)
Type of resource:
  • Text:
    • Ref. material
  • Geological Sciences:
    • Geologic time
Technical requirements:
Adobe Acrobat reader
Cost / Copyright:
No cost
All files associated with this page are copyrighted 1997 - 2005 by the Kentucky Geological Survey, University of Kentucky. Permission is granted to copy these sheets for instructional purposes.
DLESE Catalog ID: DLESE-000-000-008-551
Educational standards:
  • National Science Education Standards (NSES):
    • K-4:
      • Unifying concepts and processes:
        • Evidence, models, and explanation
      • D - Earth and space science:
        • Changes in earth and sky
    • 5-8:
      • Unifying concepts and processes:
        • Evidence, models, and explanation
      • C - Life science:
        • Diversity and adaptations of organisms
      • D - Earth and space science:
        • Earth's history
    • 9-12:
      • C - Life science:
        • Biological evolution
Related resources:
This resource is part of 'Kentucky Geological Survey: Earth Science Education Network'
Resource contact / Creator / Publisher:
Publisher: University of Kentucky
Kentucky Geological Survey