⏳ Geologic Time Explorer

Journey through 4.6 billion years of Earth's history

📋 How to Use This Simulation
  1. Click and drag on the timeline to explore different time periods
  2. Click an era (colored sections) to learn about that time period
  3. Click a fossil to learn when that organism first appeared
  4. Notice the extinction markers (💀) showing mass extinction events
  5. Use zoom buttons to focus on recent or deep time
4.6 billion years ago Present
Precambrian
Paleozoic
Mesozoic
Cenozoic
0 Mya

📅 Select an Era

Click on a colored section of the timeline to learn about that era.

📊 Time Statistics

Earth's Age: 4.6 billion years

Life on Earth: ~3.8 billion years

Complex Life: ~541 million years

🦴 Fossil Information

Click on a fossil icon below the timeline to learn when that organism first appeared and what it tells us about Earth's history.

Data Journal — Record & Analyze Your Experiments
#Observation
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💡 Key Concepts

  • Precambrian (4.6 Bya - 541 Mya): 88% of Earth's history! Simple life, stromatolites, first oxygen
  • Paleozoic (541-252 Mya): "Ancient Life" - Fish, amphibians, reptiles, first forests
  • Mesozoic (252-66 Mya): "Middle Life" - Age of Dinosaurs, first mammals and birds
  • Cenozoic (66 Mya-Present): "Recent Life" - Age of Mammals, humans appear ~300,000 years ago
  • Mass Extinctions: 5 major events shaped life's evolution, creating opportunities for survivors

🤔 PREDICT

If you could only see fossils in one rock layer, could you determine its age? What information would you need?

👀 OBSERVE

Which era takes up the most space on the timeline? Why might this be surprising given how much we know about dinosaurs?

💬 EXPLAIN

How do fossils help scientists determine the relative age of rock layers? Why are some fossils better "index fossils" than others?

Record Your Observations

As you explore Geologic Time G7 C7 W2, record what you notice:

  1. Starting conditions: What are the initial settings?
  2. Changes: What happens when you adjust the variables?
  3. Patterns: Do you notice any patterns or relationships?
  4. Evidence: What specific data supports your observations?