Clues from Fossils Fossils give us information about living things in the past.

What Can you learn from fossils?  Scientists use clues from fossils to learn about the past.

How Fossils Form  When a plant or animal dies, the soft parts quickly decay. Hard parts are left behind. teeth bones shells

Sedimentary Rocks  Most fossils are found in sedimentary rocks.  The remains are quickly buried by the sediments.

Imprints  Sometimes a shallow print or impression is the only evidence that a animal or plant ever existed.

Molds  Shells often leave behind fossils known as molds.  It is a hollow form with a particular shape.

Molds  A mold forms when water seeps into the rocks where a shell is buried.  The water dissolves the shell, which leaves a hollow space where the shell once was.

Coral Fossil

Dinosaur Tracks

Cast  A cast is formed or shaped in a mold when minerals slowly accumulate in a mold. They take the shape of the original shell and form a copy.

Cast

Trilobite

Ancient Fish

Sharks Tooth

Glen Rose, Texas

Other Ways Fossils Form  Amber  Sometimes entire insects became trapped in sticky sap oozing from certain trees.