Dinosaur Tracks

Dinosaur Tracks

Squish, squish, squish. Have you ever watched your feet making tracks in the warm sand? The beach is a great place for making footprints, and so are the muddy places at the playground after a day of rain. All over the earth, people and animals are walking, running, hopping, and jumping. They are making tracks.

More than sixty-five million years ago-millions of years before any people or any moose or any elephants ever lived-dinosaurs walked the earth. They stomped through forests. They strode across deserts. They splooshed through gloppy mud and wet sand. Wherever they went, they left footprints behind them.

Unfortunately, most footprints get washed away by rain, waves, or floods. Or they dry out and blow away in the wind. But once in a while some tracks become fossilized. Imagine an allosaur strolling down to a quiet stream for a drink of water. As he walks, he leaves a trail of footprints in the mud along the stream bank.

After the dinosaur has gone, the stream gently rises and spreads a layer of fine sand over his footprints. A few years later, the tracks get buried in a layer of mud. Groundwater with carbonate dissolved in it slowly seeps through the layers. Carbonate is a type of natural cement.

The cement in the mud makes it turn into solid stone. Now the dinosaur's tracks have become fossilized. Year after year, more layers build up over the solid layer of tracks. For millions of years the fossilized tracks lie deep underground.