Mon Prof Augmenté
Rock Layers and Fossils
Rock layers form one after another, so the oldest lie at the bottom. Fossils trapped in each layer show what lived at that time, from dinosaurs to early human relatives.
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Age 14: open this week
Browse Age 14
In the picture
- A dinosaur skeleton in the lowest layer: large ribs and spine set in dark stone
- A small mammal skeleton in the middle layer: a tiny skull and jaw in lighter stone
- A hominin skull in the upper layer: a rounded braincase and brow ridge in pale stone
- A brush and chisel on a ledge: tools resting where the layers were cleaned
Examples
- Dinosaur fossils found below fossils of early horses in the same cliff face.
- A road cut or quarry wall where older shells sit beneath newer bones.
Key takeaways
- In undisturbed rock, lower layers are older than the layers above them.
- The order of fossils in the layers shows the order in which living things appeared.
Carry on in the app
Three questions on this lesson. It has left the free week, so its quiz is for subscribers.
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