Geological time scale and fossils

• Paleozoic

  Phanerozoic eon's first era
• Paleozoic era

  541-252 m
• Paleozoic era

  • Rapid radiation of animals due to no predation
  • Life began on ocean, the first to go to land are vascular plants, Followed by lungfish
• The Borges shell

  Fossil-bearing deposit
• Amphibians

  • First vertebrates on land
• Reptiles

  • Evolved from amphibions
  • Amniote eggs allowed reptiles to reproduce on dry land
• Orogeny

  Mountain-building event
• Alleghanion orogeny

  Concluded with the Pangea
• North America

  • Separated with three different land masses, causing three different orogeny
• Carboniferous

  Paleozoic period
• Carboniferous period

  • Large deposits of coal formed during this time
  • Coal forms when plant tissues are buried in anoxic conditions, this requires fluctuation in sea level, which are caused by melting of glaciers
• Mesozoic

  Phanerozoic eon's 2nd era
• Mesozoic era

  252-66 m
• Mesozoic era

  • Age of dinosaurs (240 m)
  • Evolution of mammals (210m)
  • Pangea broke apart (180 m)
  • Ended with an asteroid (50m) that slammed the Yucatan peninsula, causing dust particles blown into the atmosphere, blocking sunlight causing darkness and global winter, resulting in 80% of all species extinct
• The great dying

  Largest mass extinction of all time, 90% of all species eradicated, caused by Siberian traps made by mantle plumes, spewing large amounts of CO2 from burning large deposits of coal and carbonate rock, causing global warming, ocean anoxia and acidification
• Cenozoic

  Phanerozoic eon's 3rd era
• Cenozoic era

  66m-present day
• Cenozoic era

  • The age of mammals, early mammals were small
  • Althatlasius (57m), 1st primate evolved from North Africa
• Petrifaction

  Fossils, minerals replace structure of organism
• Compression

  Burial of plant parts in sediment
• Mold

  Negative imprint
• Cast

  External form
• True Fossils

  Preserved original skeleton and soft body
• Ichnofossil

  Marks, traces, carvings on the wall