Paleo Sleuths - Investigating the Past Using a Geological Time Scale

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Sauropod Bones

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PBS LearningMedia


We know that the dinosaurs went extinct 66 million years ago. But what about other time markers in geologic history? How do we know what organisms lived in the past? How can we show geologic time? Geologic history is told through research done by scientists of the rock, sediment, and fossil records found in the layers of the Earth over thousands to millions to billions of years. We can show this time, from the oldest age of layers at the bottom to the youngest age of layers at the top, represented in the Geologic Time Scale. In this activity, students in groups of three will construct a vertical representation of a Geologic Time Scale and research facts, events, and organisms that differentiate between Time Scale Eras, Periods, and Epochs.

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