Geological Time Scale

Geological Time Scale

1. Precambrian

   • Bacteria
     • Photosynthesis
       • O2 poor to O2 rich
         • O3
         • UV H2O
     • Stromatolites
   • Eukaryotic cells 2100 Ma
     • Multicellular 1200 Ma
     • Sexual reproduction
       • Variation
         • Eukaryotes specialised
           • Multicellular animals
             • Ediacaran fauna

2. Phanerozoic

   • Mesozoic
     • Cretaceous
       • Flowering plants
       • K-Pg mass extinction
         • Dinosaur extinction
         • Meteorite and Volcano
           • CO2, SO2, dust
             • PH acidic
             • Photosynthesis reduced
               • Autotrophs -food source
     • Triassic
       • Mammals
         • Small
       • Dinosaurs dominate
     • Jurassic
       • Birds
   • Palaeozoic
     • Cambrian (explosion)
       • Sea
       • Chordates
         • Vertebrates
           • Jaw-less fish
       • Burrowing
       • Body organised into areas
       • Shells/skeletons
         • Excretion deposits
           • Advantageous
     • Ordovician
       • More fish, diversity
     • Devonian
       • Trees
       • Seeds
         • Inland colonised
       • Abundant fish
       • Vertebrates part-land
         • Large amphibians
       • Plant stems, root hairs
     • Silurian
       • Jawed fish
       • Plants and animals to land and freshwater
         • Insects
         • Anthopods
         • Adaptations
           • Gravity
           • Plant stomata, outer coat
     • Carboniferous
       • Reptiles
         • Shelled eggs
       • Coal
   • Cenozoic
     • Palaeogene
       • Radiation of mammals
     • Homo Sapiens