Welcome to Written in Stone
Sweep the Fossil Finder across the cliff to uncover four fossils, then put the animals in order from oldest to youngest, using how deep each fossil sits in the rock as your clue.
How do I explore?
- Move the Fossil Finder slowly across the cliff face. It warms up and points the way when you get close to a hidden fossil.
- When a fossil appears inside the glass, click it to identify it. Flip the card to see the animal that once lived here, then press Continue.
- Once you find all four fossils, put the animals in order from oldest to youngest.
What should I do/notice?
- Every fossil you find lands on your My Finds shelf. Click one there to look at its card again.
- Notice how deep in the cliff each fossil was found. Deeper rock is older.
- In the ordering activity, put the oldest animal on the left and the youngest on the right, then press Check order.
Accessibility
- Click the canvas, then use the arrow keys to move the Fossil Finder. Hold Shift to move faster.
- Press Enter or Space to identify a fossil when it is inside the glass, and to flip a fossil card.
- Stuck? Press Help me Spot them for a hint, or press I need help during the ordering activity.
- In the ordering activity, press Tab to reach a card, then use the left and right arrow keys to move it.
- Press Escape to close a card or this dialog.
Sweep the Fossil Finder across the cliff to uncover four fossils, then put the animals in order from oldest to youngest, using how deep each fossil sits in the rock as your clue.
Standards
4-ESS1-1 Identify evidence from patterns in rock formations and fossils in rock layers to support an explanation for changes in a landscape over time.
3-LS4-1 Analyze and interpret data from fossils to provide evidence of the organisms and the environments in which they lived long ago.
Design intent
- The real reasoning happens when students order the animals from oldest to youngest. Deeper layers are older, so working out that order is the 4-ESS1-1 thinking. The fossil hunt is there to draw students in.
- The backdrop is a real photograph of Badlands National Park, a place where scientists still search for fossils.
- Help stays in the background until students ask. They can search on their own, tap "Help me Spot them" if they get stuck, and open a hint during the ordering activity.
Discussion prompts
- The Fossil Finder made the search quick. A real dig can take a whole summer, sometimes years. Why do people spend so long looking for fossils?
- Scientists care about where a fossil is found, not just the fossil itself. Why does its place in the rock layers matter?
- All four animals lived in greener, wetter habitats such as woodlands and river floodplains, but the Badlands today is dry. What does that tell us about how the landscape has changed?
- Mesohippus was found higher up than Oreodont, so it is more recent. Does that mean the two animals never lived at the same time?
Model details
The five bands stand for the real Badlands rock layers, oldest at the bottom to youngest at the top. The lower bands are White River Group formations, Chadron then Brule. The top band is the younger Sharps Formation, which belongs to the overlying Arikaree Group, not the White River Group. Megacerops is a Chadron animal, since brontotheres died out before the Brule, so its fossil is reliably the deepest and oldest.
- Oreodont, Hoplophoneus, and Mesohippus all lived into the younger Brule, so they share the "Brule Formation" label. Their order in the activity comes from how deep each fossil was found, not from the formation name.
- The correct order from oldest to youngest is Megacerops, Oreodont, Hoplophoneus, Mesohippus.
- The top layer (Sharps) holds no fossil. It stands in for barren volcanic ash.
- The Fossil Finder makes buried fossils easy to spot. In real fieldwork most fossils stay buried, and a single dig can take years.