How fossils are made By Aiden Rixom What

How fossils are made By Aiden Rixom

What is a Fossil? • Fossils are remains of dead animals or plants that lived over 10, 000 years ago. The dinosaurs went extinct 65 million years ago. • They are rare because most animals and plants that die rot away. • Conditions must be perfect for fossils to form.

Step 1 A dinosaur or other animals and plants die and fall to the bottom of the ocean or get stuck in mud.

Step 2 The animal or plant is buried by things like sand, volcanic ash and mud.

Step 3 The skin, flesh and muscles rot away, leaving the skeleton behind.

Step 4 The animal or plant is covered by layers of sediment. Pressure forces the sediment layers together, turning them into sedimentary rock. That is why fossils are only found in sedimentary rock.

Step 5 Water gets into the sedimentary rock and washes the bone and shell away. You are left with a mould.

Step 6 The water fills up the mould with hard rock and minerals

Step 7 • Sedimentary rock washes away leaving the hard rock shape of the animal or plant. This is the cast. • The cast can be dug up by people.

How to make a mould • Mix flour, salt, coffee and water together to make a dough • Knead the dough • Press something into the dough and remove it. • Leave the dough to dry. • This is the mould.

My Fossil Mould