Contents
Key Stage 2
Meaning
A fossil is a piece of a dead creature that has turned into rock over millions of years.
About Fossils
- A fossil begins as a creature that dies and falls into mud or sand.
- Over millions of years the mud or sand turns into a rock with the creature trapped inside.
- The creature is replaced by minerals leaving a rock that is the same shape as the creature.
- In animals it is usually only the bone that becomes a fossil.
Evidence of Evolution
- Fossils show us many creatures that do not exist anymore.
The Tyrannosaurus Rex is a dinosaur that became extinct 66 million years ago. | The Giant Sloth lived in North America and became extinct 10,000 years ago at the end of the last Ice Age. |
The Dimetrodon became extinct long before the dinosaurs even existed. | The Moa has only been extinct for about 500 years. |
- Fossils appear slightly different as you dig into older rocks. When you dig far enough the oldest fossils look very different to the modern creatures.
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Key Stage 3
Meaning
Fossils are the remains of a dead organisms that became trapped in sedimentary rock and turned into rock themselves over millions of years.
About Fossils
Key Stage 4
Meaning
Fossils are the remains of a dead organisms that became trapped in sedimentary rock and turned into rock themselves over millions of years.
About Fossils
- Most animal fossils come from the bones, teeth and shells of animals which have been trapped under layers of sedimentary rock. While there the biological material has been gradually replaced by minerals turning it into rock over millions of years.
- Some fossils are made when organisms become trapped in an anoxic environment where they cannot decay such as within amber, tar pits or under layers of ice.
Fossils as Evidence
- Fossils are one of the lines of scientific evidence for evolution.
- Since sedimentary rocks build up in layers over time fossils found in deeper layers are from further in the past. This can be used to date the fossils telling us when the organism died.
- Fossils provide a number of transitional forms showing how some speciess which are not extinct gradually evolved over time to form the species that are alive today.
- The fossil record is not complete as fossilisation is a rare process, so very few organisms become fossils after death. However, there are enough records to show clear evidence of evolution.
References
AQA
- Fossil, page 280-3, GCSE Biology; Student Book, Collins, AQA
- Fossils, page 101, GCSE Biology; The Revision Guide, CGP, AQA
- Fossils, pages 219-20, GCSE Biology, Hodder, AQA
- Fossils, pages 243, 244, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Fossils, pages 301, 302, GCSE Biology, CGP, AQA
- Fossils, pages 59, GCSE Combined Science Trilogy 2, Hodder, AQA
Edexcel
- Fossils, pages 126, 130, 131, 134, GCSE Biology, CGP, Edexcel
- Fossils, pages 32, 33, GCSE Combined Science; The Revision Guide, CGP, Edexcel
- Fossils, pages 45, 47, GCSE Biology; The Revision Guide, CGP, Edexcel