<ul><li>Fossils  are preserved remains or traces of living things. </li></ul><ul><li>Most fossils form when living things ...
<ul><li>Fossils are usually found in  sedimentary  rocks. </li></ul><ul><li>When an organism dies, its soft parts often de...
<ul><li>Petrified Fossils : fossils in which minerals replace all or part of the organism. Ex: petrified wood </li></ul><u...
<ul><li>Molds and Casts </li></ul><ul><li>A  mold  is a hollow area in sediment in the shape of an organism or part of an ...
<ul><li>Carbon Films :  an extremely thin coating of carbon on rock that forms when materials that make up an organism bec...
<ul><li>Preserved Remains  are formed when an organism is preserved with little or no change. </li></ul><ul><li>For exampl...
<ul><li>Scientists study fossils to learn what past life forms were like. </li></ul><ul><li>Paleontologists classify organ...
<ul><li>The fossil record provides evidence about the history of life on Earth. </li></ul><ul><li>The fossil record also s...
<ul><li>A scientific theory is a well-tested concept that explains a wide range of observations. </li></ul><ul><li>The fos...
 
 
<ul><li>The  relative age  of a rock is its age compared to other rocks.  Use words like: “older or younger” </li></ul><ul...
<ul><li>What does a rock want to be when it grows up? </li></ul><ul><li>A Rock Star!! </li></ul>
<ul><li>It can be difficult to determine a rocks absolute age. So… scientists use the  law of superposition . </li></ul><u...
<ul><li>How do rocks wash their clothes? </li></ul><ul><li>The Rock Cycle!! </li></ul>
<ul><li>Clues From Igneous Rock </li></ul><ul><li>Lava that cools at the surface is called an extrusion. Rock below an ext...
<ul><li>Faults  (a break in the rock) are always younger than the rock  it cuts through! </li></ul><ul><li>Unconformities ...
<ul><li>Scientists use index fossils to match rock layers.  </li></ul><ul><li>An  index fossil  must be widely distributed...
<ul><li>One example of an index fossil is a trilobite. </li></ul><ul><li>Trilobites were a group of hard-shelled animals w...
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Studying Fossils

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Studying Fossils

  1. 2. <ul><li>Fossils are preserved remains or traces of living things. </li></ul><ul><li>Most fossils form when living things die and are buried by sediments. </li></ul><ul><li>The sediments slowly harden into rock and preserve the shape of the organisms. </li></ul><ul><li>Scientists who study fossils are paleontologists. </li></ul>
  2. 3. <ul><li>Fossils are usually found in sedimentary rocks. </li></ul><ul><li>When an organism dies, its soft parts often decay quickly leaving only the hard parts to fossilize. </li></ul><ul><li>Ex. Bones, Shells, Teeth, or Seeds </li></ul>
  3. 4. <ul><li>Petrified Fossils : fossils in which minerals replace all or part of the organism. Ex: petrified wood </li></ul><ul><li>When the object is buried by sediment, water rich in minerals seeps into the cells. After the water evaporates, hardened minerals are left behind. </li></ul>
  4. 5. <ul><li>Molds and Casts </li></ul><ul><li>A mold is a hollow area in sediment in the shape of an organism or part of an organism. </li></ul><ul><li>A cast is a copy of the shape of an organism. </li></ul>
  5. 6. <ul><li>Carbon Films : an extremely thin coating of carbon on rock that forms when materials that make up an organism become gases and escape leaving only carbon behind. </li></ul><ul><li>Trace Fossils provide evidence of the activities of ancient organisms. Ex: footprints, animal trails, or animal burrows. </li></ul>
  6. 7. <ul><li>Preserved Remains are formed when an organism is preserved with little or no change. </li></ul><ul><li>For example when organisms become preserved in tar, amber (tree sap), and freezing. </li></ul>
  7. 8. <ul><li>Scientists study fossils to learn what past life forms were like. </li></ul><ul><li>Paleontologists classify organisms in the order in which they lived. </li></ul><ul><li>All the information scientists have gathered is called the fossil record . </li></ul>
  8. 9. <ul><li>The fossil record provides evidence about the history of life on Earth. </li></ul><ul><li>The fossil record also shows how different groups of organisms have changed over time. </li></ul><ul><li>It also provides evidence to support the theory of evolution. </li></ul>
  9. 10. <ul><li>A scientific theory is a well-tested concept that explains a wide range of observations. </li></ul><ul><li>The fossil record shows that millions of types of organisms have evolved. </li></ul><ul><li>However, many others became extinct. </li></ul>
  10. 13. <ul><li>The relative age of a rock is its age compared to other rocks. Use words like: “older or younger” </li></ul><ul><li>The absolute age of a rock is the number of years since the rock was formed. </li></ul><ul><li>Ex: 358-360 mya </li></ul>
  11. 14. <ul><li>What does a rock want to be when it grows up? </li></ul><ul><li>A Rock Star!! </li></ul>
  12. 15. <ul><li>It can be difficult to determine a rocks absolute age. So… scientists use the law of superposition . </li></ul><ul><li>According to the law of superposition , in horizontal sedimentary rock layers the oldest layer is at the bottom. Each higher layer is younger than the layers below it. </li></ul>
  13. 16. <ul><li>How do rocks wash their clothes? </li></ul><ul><li>The Rock Cycle!! </li></ul>
  14. 17. <ul><li>Clues From Igneous Rock </li></ul><ul><li>Lava that cools at the surface is called an extrusion. Rock below an extrusion is always older. </li></ul><ul><li>Magma that cools beneath the surface is called an intrusion. An intrusion is always younger than the rock layers around an beneath it. </li></ul>
  15. 18. <ul><li>Faults (a break in the rock) are always younger than the rock it cuts through! </li></ul><ul><li>Unconformities : An unconformity is a gap in the geological record that can occur when erosion wears away rock layers and other rock layers form on top of the eroded surface. </li></ul>
  16. 19. <ul><li>Scientists use index fossils to match rock layers. </li></ul><ul><li>An index fossil must be widely distributed and represent a type of organism that existed only briefly. </li></ul><ul><li>They are useful because they tell the relative ages of the rock layers they are found in. </li></ul>
  17. 20. <ul><li>One example of an index fossil is a trilobite. </li></ul><ul><li>Trilobites were a group of hard-shelled animals whose bodies had three distinct parts. </li></ul><ul><li>They evolved in shallow seas more than 500 million years ago. </li></ul>

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