View mindmap
  • Fossils
    • Gradual Replacement
      • teeth, bones, shells, don't decay
        • instead they are replaced over long periods of time by minerals
      • this is how most fossils are formed
    • Casts and impressions
      • Things are buried in soft surfaces eg clay
        • clay hardens and as creature decays cast is left of where it was
      • also footprints can be retained as impressions
      • animals burrows can be retained
    • Preservation
      • If an animal dies in a place where conditions for decay are missing
        • eg a peat bog is too acidic
        • eg a glacier is too cold
        • Decay microbes need oxygen and moisture or they can't work
    • can show us how species developed
      • show similarities to present day animals
        • Untitled


No comments have yet been made

Similar Science resources:

See all Science resources »See all Crude oil and fuel resources »