Unit 4 — Dating Planet Earth

Science — Third Preparatory

1.1 How do we know that dinosaurs lived millions of years ago?

Nobody saw dinosaurs, yet we know a great deal about them.
The evidence comes from fossils.
Imagine you find a line of footprints in a sandy area.
What do they tell you?
You can tell what kind of animal walked there (from the shape and size), roughly how big it was, how many animals, the direction they were going, and even whether the animal was walking or running (from spacing).
In the same way, scientists "read" fossils as clues to events of long ago.

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