Fossils and Extinction

• Fossils


  Remains of organisms from millions of years ago which are found in rocks
• Extinction


  When there are no remaining individuals of a species still alive
• Reasons for extinction

  • New predator
  • Competition for food/mates
  • New disease
  • Catastrophic event
  • Hunting
  • Climate change
  • Destruction of habitats
• Why is there an incomplete fossil record?

  • Early life forms were soft-bodied so decayed easily leaving no traces
  • Destroyed by geological activity
• How fossils are formed

  • Replaced by minerals as they decay
  • Footprints, burrow, rootlet traces
  • Trapped in amber (no decay as there is no oxygen)