🦴 Fossils
A five-minute lesson. Tap play and I’ll read every step, or read along and tap 🔊 on any step.
What is a fossil?
A fossil is what is left of a living thing from long ago, kept in rock: a bone, a tooth, a shell, or a footprint.
Bone to stone
When an animal is covered quickly by mud or sand, layers pile on top over a very long time. Minerals slowly fill the bone and turn it to stone.
Digging it out
Scientists who look for fossils dig slowly with small brushes and picks, and wrap big bones in plaster to carry them safely.
Clues in the rock
Footprints show how an animal walked. Nests of eggs show how dinosaurs looked after their young.
Layers tell the order
Rock is laid down in layers, so lower layers are usually older. A fossil low down lived before one higher up.
Clues about places
Fossils of sea animals found in a desert tell us that the place was once under the sea.
Quiz: three questions
Draw it, and try it at home
Draw rock layers, like a layer cake. Put an older fossil low down and a newer one higher up, and label which is older. Then try this at home: Press a leaf, a shell or a toy into play dough. Lift it out carefully. Look at the print it leaves: that's how a trace fossil forms.
For teachers: Grades 2–4
- NGSS 3-LS4-1: Fossils give evidence of the organisms and the environments in which they lived long ago.