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Fossils. Remains of Ancient Plants And Animals, Evidence of Life . Commonly Preserved:. Hard Parts of Organisms: Bones Shells Hard Parts of Insects Woody Material . Rarely Preserved. Soft or Easily Decayed Parts of Organisms: Internal Organs Skin Hair Feathers. Types of Fossils.
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Fossils Remains of Ancient Plants And Animals, Evidence of Life
Commonly Preserved: Hard Parts of Organisms: • Bones • Shells • Hard Parts of Insects • Woody Material
Rarely Preserved Soft or Easily Decayed Parts of Organisms: • Internal Organs • Skin • Hair • Feathers
Types of Fossils • Original Material • Casts & Molds • Replacement (Petrified Wood) • Carbonized Films (Leaves) • Footprints, Tracks, Etc. • “Trace Fossils” – Our only preserved record of behavior of fossil organisms
Pseudofossils Look Like Fossils But Aren't • Dendrites • Concretions
Where Fossils Occur Almost Exclusively in Sedimentary Rocks • Heat of Melting or Metamorphism Would Destroy Almost Every Type of Fossil • Rare Exceptions: • Some Fossils in Low-grade Metamorphic Rocks • Trees Buried by Lava Flow To Be Preserved, Organisms Have to Be: • Buried Rapidly After Death • Preserved From Decay
Good Index Fossils • Abundant • Widely-distributed (Global Preferred) • Short-lived or Rapidly Changing
Correlation Correlation