Fossils

• Fossils

  • remnants, impression or trace of an animal or plant of a PAST geologic age that has been preserved in earth's crust.
• Types of Fossils

  1. Molds
  2. Casts
  3. Permineralized or Petrified
  4. Original Remains
  5. Carbonaceous Films
  6. Ichnofossils/Trace
• Molds

  • Organism dissolve away, LEAVING IMPRINT
  • E.g. - shells
• Casts

  • Sediments fill in mold and harden into rock
  • Look like original, but LOSES INTERNAL SHAPE and BECOMES ROCK
  • E.g. - bones and teeth
• PERMINERALIZED OR PETRIFIED

  • Organic mineral can be converted into stones
  • Most real dinosaur bone, petrified woods
• Original Remains

  • ACTUAL ORGANISM or part PRESERVED
  • Mammoth freeze-dried remains of a woolly mammoth
• CARBONACEOUS FILMS

  • All life contains CARBON
  • Carbonization
  • Carbon impression in sedimentary rock
  • E.g. - leaf impressions on the rock
• Ichnofossils / Trace

  • movements and behaviors of the organism
  • Imprints left rock / mud by living animal
  • Trails and burrow made by WORMS and other animals