History of Life on Earth:

 History of Life on Earth: Eon -> Era -> Periods -> Epochs

1. Hadean (Eon): 4.6-4.0 billion years ago 

   1. Earth formed

   2. Moon is formed

2. Archaean (Eon): 4.0 - 2.5 billion years ago

   1. First Prokaryotes

      1. First Archaea

      2. First Bacteria

      3. Fermentation 

   2. First Cyanobacteria

      1. Photosynthesis

   3. Oxygen in atmosphere increases

      1. Cellular Respiration 

   4. Mass extinction at the end

3. Proterozoic (Eon): 2.5-0.5 billion years ago 

   1. First Eukaryotes

      1. First Protista 

   2. Ediacaran (Period): First animals

      1. First Porifera - sponges

      2. First Cnidaria - jellyfish

4. Phanerozoic (Eon): 0.5 - 0.0 billion years ago 

   1. Paleozoic (Era): 500-250 million years ago

      1. Cambrian (Period) 

         1. Cambrian Explosion: increased diversity of animal phyla

         2. First Platyhelminthes - flatworms

         3. First Nematoda - roundworms

         4. First Mollusca - mollusks

         5. First Annelida - segmented worms

         6. First Arthropoda - arthropods

         7. First Echinodermata - echinoderms

         8. First Chordata - chordates

            1. Agnatha - jawless fish

      2. Ordovician (Period)

         1. Colonization of land

            1. First Fungi 

            2. First non-vascular plants

      3. Silurian (Period):

         1. First evolve jaws for biting

         2. First early vascular plants

         3. First arthropods on land

            1. Millipedes

            2. Arachnids

      4. Devonian (Periods)

         1. Age of Fish

            1. First Chondrichthyes - sharks

            2. Firsy Osteichthyes - bony fish

         2. Land

            1. First Insecta - Insects

            2. First Amphibia - Amphibians

            3. First Pteridophyta - Ferns

      5. Carboniferous (Period)

         1. Land Plants

            1. Ferns dominant

         2. First Gymnosperms

            1. Coniferophyta - conifers

         3. Land Animals

            1. Amphibians dominant

            2. First Reptilia - reptiles

      6. Permian (Period)

         1. Pangea: supercontinent

         2. Land Plants

            1. First Cycadophyta - cycads

            2. First Ginkgophyta - ginkgos

         3. Land Animals

            1. Diversification of reptiles

   2. Mesozoic (Era): 250-65 million years ago

      1. Triassic (Period) 

         1. Archosaurs - ancient crocodiles 

         2. First dinosaurs - small theropods

         3. First Mammalia

      2. Jurassic (Period)

         1. Dinosaurs dominant

            1. Sauropods - longneck herbivores

            2. Theropods

               1. Large carnivores

         2. Pterosaurs - flying reptiles

      3. Cretaceous (Period) 

         1. Plants

            1. Gymnosperms dominant

            2. First Angiosperms: flowering plants

         2. Animals 

            1. Dinosaurs dominant

            2. First Aves: birds

         3. MASS EXTINCTION- rapid extinction of 50-90% of ALL species

   3. Cenozoic (Era): 65-0 million years ago

      1. Paleogene (Period)

         1. Adaptive radiation: rapid speciation to fill emptied habitats after extinction

            1. Angiosperms, mammals, birds dominant

         2. First Primata

      2. Neogene (Period)

         1. First Hominidae

         2. Bipedal human ancestor

      3. Quaternary (Period)

         1. Pleistocene (Epoch): Ice Age

            1. Large land mammals 

            2. First Genus Homo

               1. Homo habilis 

               2. Homo erectus

               3. Homo sapiens

         2. Holocene (Epoch): Modern History

            1. 10,000 BCE - Present

            2. Anthropocene: evidence of human impact on fossil record