mass extinctions

• Trilobites, cephalopods, corals


  • Affected by the largest mass extinction
• Mass extinction


  A significant proportion of species become extinct (>30%) and it affects a wide range of environments, occurring rapidly over a few million years
• The end of the cretaceous was when 70% of all species were wiped out, dinosaurs (not birds), ammonites, belemnites and some brachiopods became extinct
• Groups affected by the end of the cretaceous mass extinction

  • Dinosaurs (not birds)
  • Ammonites
  • Belemnites
  • Some brachiopods
• The largest mass extinction was at the end of the Permian, 95% of all marine species died and 50% of marine families
• Rock records


  Show long periods of slow changes interrupted by sudden catastrophises that causes mass extinctions through time
• Effects of the largest mass extinction

  • Trilobites
  • Cephalopods
  • Corals
• Reasons for mass extinctions

  • Supercontinent formations
  • Extra-terrestrial impacts
  • Flood basalt eruptions
  • Methane hydrates and global warming
  • Rapid and major glaciation events