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Here's Lumi by a creek with her class. She turns over a flat gray rock.

On it is the shape of a fish, bones and all. But there's no fish, just its shape in the rock.

Now let's look where Sid is pointing. A footprint in the rock, bigger than his head.

Who left these marks? How long ago? And how did they last, inside rock?

Now let's look up at the dry hill. Its rocks are full of sea shells, and the sea is miles away.

That's what this topic is about: the few dead things that last, and what they tell us about long ago.

Okay, so are you ready to find out what fossils can tell us?

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