Fossils

• Fossils

  • Remains or trace of prehistoric life preserved in sedimentary rocks, naturally preserved and are older than 10,000 years
• Sessile - fixed in one place/permanently attached or established: not free to move around
• Fossils not in life position

  • It means that they are not a permanent sessile
• Example of fossils that are in life positions are corals
• Requirements for fossilization:

  1. Rapid Burial
  2. Protective medium
  3. Possession of Hard parts
• Types of Fossilization

  1. Preservation of unaltered parts
  2. Chemical alteration of hard parts
  3. Imprints of hard parts in sediment or trace fossils
• Chemical alteration of hard parts

  1. carbonization
  2. dissolution and replacement
  3. recrystallization
  4. permineralization
  5. petrifaction
• petrifaction

  • process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals. 
• Permineralization

  • Porous material filled with secondary materials (bone permineralized with silica)
• Mold and cast

  
• Borings and burrows

  
• Coprolites (poop)

  
• Gastroliths (rocks eaten/ digestive rocks)

  
• Oldest fossils in the philippines

  • Mindoro: Rugose coral
• Oldest fossils in the philippines

  • Palawan: Fusulinids
• Oldest FOssils in the philippines

  1. Rugose coral (mindoro)
  2. Fusulinids (palawan)
  3. Earliest hominin activity
• Uses of Fossils

  • Tracing the evolutionary history of extinct as well as living organisms
  • Reconstructing paleoclimates and paleoenvironments
  • Providing the source of energy resources (e.g. oil, gas, coal)
• Geologic Time Scale

  • The history of the earth is broken up into a hierarchical set of divisions for describing geologic time.
• Units of time include eon, era, period, epoch, age
• Eon > Era > Period > Epoch
• Pleistocene - last ice age
• Cretaceous-Tertiary

  • extinction of dinosaurs
• Permian-Triassic

  • extinction of 96% marine life
• Carboniferous

  • proliferation of plants
• Devonian

  • proliferation of fish
• Cambrian

  • explosion of life (algae, invertebrates, marine life)
• Pre-cambrian

  • no complex life, planet developing, atmosphere forming, earth cooling down
• Pleistocene - 10,000 ya
• Cretaceous-tertiary: 65 mya
• Permian-Triassic: 250 mya
• Carboniferous: 300-370 mya
• Devonian: 460 mya
• Cambrian: 542 mya
• Pre-cambrian: 542 mya - 4.6 bya