Questions and Answers
Most fossils are found in what type of rock?
Why are most fossils found in sedimentary rock?
Organisms die and are usually buried by sediments, or organisms leave imprints in sediments.
Which type of environment will result in good fossil specimens?
What type of fossil will be found in a high-energy environment?
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Can fossils occur in volcaniclasts?
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Are fossils found in intrusive igneous rocks?
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What happens to fossils when they go through metamorphism?
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What is the first step in forming a fossil?
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What is the second step in forming a fossil?
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What is the next step in fossil formation after bones/prints are covered?
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What is the next step after bones/prints are covered by sediments?
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What happens next in the fossilization process?
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What is the next step after minerals replace the bones?
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What is the final step in the fossilization process?
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What are the 6 kinds of fossils?
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What is a body fossil?
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What is a replaced bones/teeth/shells fossil?
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What is a mold fossil?
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What is a cast fossil?
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What type of fossil is formed from soft or semi-soft organisms being pressed flat between layers of sediment?
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What is a permineralization fossil?
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What is a trace fossil?
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What type of fossils can be seen with the naked eye?
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What type of fossils can only be seen with an electron microscope?
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What type of organisms commonly make microfossils?
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What are the three special conditions required for fossilization?
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When did archaea and bacteria appear?
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When did the first eukarya plankton (protists) appear?
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When did the first fungi appear?
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When was the Cambrian explosion?
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Study Notes
Fossil Formation and Types
- Most fossils are found in sedimentary rock due to the conditions conducive to preservation.
- Organisms typically die and get buried under sediments, or leave imprints in sediment as they move.
- Quiet water environments are ideal for high-quality fossil specimens.
Fossilization Process
- Step 1: Organism dies, leaving behind its body or footprints.
- Step 2: Flesh decays, leaving bones or prints.
- Step 3: Bones/prints get covered by sediments.
- Step 4: Sediment undergoes lithification, turning into rock.
- Step 5: Groundwater minerals replace the bones.
- Step 6: Bones transform into rock-like structures (fossilization).
- Final Step: Erosion or uplift exposes the fossil.
Types of Fossils
- Body Fossils: Complete or parts of an organism preserved, e.g., woolly mammoth in permafrost.
- Replaced Fossils: Hard parts (bones, teeth, shells) preserved through durable materials.
- Mold Fossils: Impressions left in rock after the hard part dissolves, e.g., calcite shells.
- Cast Fossils: Formed by sediment filling molds that become lithified.
- Carbonized Impressions: Formed from soft organisms pressed flat between sediments.
- Permineralization: Minerally-filled porous materials create fossils.
- Trace Fossils: Indicators of activity (footprints, burrows, feeding traces).
Fossil Visibility
- Macrofossils: Visible to the naked eye.
- Microfossils: Require electron microscopes to observe; include plankton, pollen, algae, and bacteria.
Conditions for Fossilization
- Fossilization requires three specific conditions:
- An anoxic environment (low oxygen).
- Rapid burial of the organism.
- Presence of hard parts within the organism.
Key Geological Timeline
- 3.7 billion years ago (BYA): First appearance of archaea and bacteria.
- 2.5 BYA: Emergence of the first eukaryotic plankton (protists).
- 1.5-1 BYA: Introduction of the first fungi.
- 530 million years ago (MYA): The Cambrian explosion marks significant biodiversity increase.
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Description
Test your knowledge of fossils with this set of flashcards! Learn about the types of rocks where fossils are typically found, the conditions that contribute to the formation of fossils, and the best environments for fossil preservation. Perfect for students seeking to deepen their understanding of paleontology.