Mr. Harper’s science mini lesson with audio

1. Fossils The remains of organisms that lived long ago Mr. Harper’s science mini lesson with audio

2. When an organism is eaten by another organism there may be nothing left over. //

3. Any part of an organism that still exists after it dies is called the remains of the organism. //

4. If a tree dies in the forest, its remains may stay on the ground for years. //

5. After a time, the remains of the tree begin to decompose and become part of the soil. //

6. The remains of any animal that are exposed to the air or buried in soil will not be preserved. They will be gone in a few weeks if they are not protected from being decomposed. The harder bones last longer but in time they also will break down and become part of the soil. //

7. To preserve something means to keep it from being destroyed. Fresh food can be preserved for months or years if it is sealed in air tight jars or cans.

8. Ancient Egyptians preserved the remains of dead people for thousands of years as mummies. //

9. But under certain conditions, the remains of plants and animals can be naturally preserved. Very old remains are called fossils. Some fossils are millions of years old. //

10. Fossils can be preserved if the organism was buried in sediment (such as mud) soon after it died. //

11. If the sediment containing the remains becomes sedimentary rock, the fossil can be discovered inside the rock. //

12. Fossils can only be preserved in sedimentary rock. The processes that make igneous rock and metamorphic rock would destroy any fossils. //

13. Sometimes the remains are gone but an imprint is left in the rock. This is still a fossil. Footprints of animals that lived long ago are called trace fossils. //

14. Sometimes an organism decomposes and leaves a space in the rock that fills up with minerals. If the minerals harden in the shape of the organism, it forms a cast fossil also called a mold fossil.

15. Some fossils give us evidence (proof) of plants and animals that no longer live on Earth. If all members of an organism have died off, that organism is said to be extinct. Almost all the dinosaurs became extinct after a huge meteor hit Earth about 65 million years ago. //

16. Of course when the actual remains (very old bones) are found, they are fossils. Dinosaur remains are fossils that are at least 65 million years old. //

17. Scientists who specialize in fossils are called paleontologists. People who visit the Page Museum in Los Angeles can see paleontologists at work.

18. The Page Museum in Los Angeles is a place to see many fossils from 10,000 to 40,000 years ago that were preserved in asphalt and excavated from the La Brea Tar Pits. //

19. And then there are fossil fuels. Plants and animals contain energy. If they are eaten, that energy goes into the animal that eats it. The energy in a tree can be released as heat and light energy if the wood is burned.

20. There were times long ago when the remains of a lot of plants and animals just piled up on the ground or at the bottom of the ocean. The energy in them wasn’t eaten or burned. All that energy was buried in mud, trapped underground.

21. For millions of years, plants that died were buried by layers of other plants. The energy in the plants was preserved in a black rock called coal.

22. During that time, the remains of billions of sea animals piled up on the ocean floor and were covered with mud. The energy in those animals was preserved in black oil called petroleum. .

23. In the last few hundred years, people have been digging and drilling into the Earth’s crust to bring that fuel made from fossils to the surface. Oil well pumping crude oil from deep underground. Railroad cars filled with coal. Coal mining underground. crude oil HOW OIL WAS FORMED HOW COAL WAS FORMED

24. Today we use fossil fuels made from coal and petroleum for energy in many ways. //

25. Now, let’s review to see how much you remembered.

26. Review: What word means “to protect something so it isn’t destroyed.”

27. Review: Preserve means to protect something so it isn’t destroyed. The remains of this spider have been preserved in a clear mineral called amber. Sedimentary rocks are the only rock that can preserve fossils.

28. Review: What word means “the parts of an organism that still exist after it dies.”

29. Review: Remains is the word for any part of an organism that still exists after it dies.

30. Review: What word means “the remains of an organism that lived a long time ago.”

31. Review: A fossil is what we call the remains of an organism that lived long ago

32. Review: What is the only type of rock in which fossils can be found?

33. Review: Sedimentary rock is the only type of rock that can preserve a fossil. Igneous and metamorphic rock formation would destroy any fossils. Sedimentary rock formation Igneous rock formation Metamorphic rock formation - weathered sediment is pressed together - rock is melted an cooled - rock is heated and put under great pressure

34. Review: What term means “energy sources made from the remains of plants and animals that died long ago.”

35. Review: Fossil fuel is the term for petroleum and coal that contain energy from organisms that lived long.

36. Note: Coal is not the same thing as charcoal that you may have seen in a barbeque grill. Coal burns very hot and makes nasty smoke. A coal fire would ruin the food and probably melt a barbeque grill. Charcoal burns clean and can be used for cooking.

37. You can learn more about fossils with these Brainpop cartoons: // • Fossils • Dinosaurs • Extinction • Geologic time