Quaternary (1.8 ma to today)
       Holocene
       (10,000 years to today)


       Pleistocene
       (1.8 ma to 10,000 yrs)

• Less than 2,000 years ago: Recorded Human History.
• Iron Age
• Bronze Age
• Possible major impact event leading to Great Flood?
• 10,000 years ago : Modern Man.
• Upper Paleolithic : Neolithic
  (End of late Stone Age).
• Holocene Extinction ongoing event during the modern era. Includes plants and large mammals known as megafauna due to the last Ice Age and the proliferation of modern humans.

• Pleistocene or Ice Age Extinction Event.
• 12-17,000 yrs ago: End of Little Ice Age.
• 100,000 yrs ago : Neanderthal Man
• 300,000 yrs ago : Mesolithic
  (Middle Stone Age).
• 400,000 yrs ago : Homo Sapiens.
• 700,000 yrs ago: Homo Erectus.
• 1,100,000 yrs ago: Worldwide Ice Age ends.

• Great Ice Age. 1/3 of all land covered by glaciations. Tertiary-Quaternary boundary.
• Many smaller extinctions. Mainly a series of interglacial events. Sea levels and temperatures rise and fall. Tiny shell-bearing sea creatures lost.
• 2.5 Ma Homo habilis
  (Paleolithic, Old Stone Age).
• Early grazing animals including horse.
• Early primates, cats, dogs, rabbits.
• Small mammals : rats, mice, squirrels have changed from egg laying to viviparity (placental).
• Alps form due to collision of the European and African tectonic plates.

• 65 Million Years : Dinosaurs became extinct, plus up to 50% of all other species.
• Cretaceous-Paleogene Transition extinction event:
• K-T Boundary Layer supports impact theory. Possibly by multiple impacts by disrupted Carbonaceous asteroid or comet broken up in the atmosphere. Possible event sites: Chicxulub Crater, centered on Yucatan Peninsula, Mexico. Silverpit Crater (North Sea area) UK. & Boltysh Crater, Ukraine.
• Rocky Mountains form due to tectonic plate collision, and subduction of old seabed.
• First modern Birds.
• Primitive marsupial mammals like Kangaroos.
• Age of Reptiles.
  

• Minor Mass Extinctions linked to an oceanic anoxic event. Ammonoids affected.
• Pangaea super continent separates.
• Dinosaurs dominant
• Early flowering plants.
• Early birds and primitive mammals.
  

• Triassic-Jurassic Transition : Mass extinction : 20-35% lost. Most early dinosaur families, many marine invertebrates and mammal-like reptiles.
• Fist dinosaurs and first egg-laying mammals.
• First flying vertebrates, the pterosaurs, (toothed birds).
• Opening of the Atlantic due to tectonic plate movements.
• Climate generally hot and dry forming red bed sandstones and evaporites.
• Polar regions moist and temperate.
• Adaptive radiation (after mass extinction): rapid evolution diversification of a few species to fill many ecological niches. By natural selection, adaptation or mutation.

• P/Tr or Permian-Triassic extinction event. Largest Mass extinction : 95% of all marine life + 70% of land species lost.
• Theory : Meteorite Impacts affected Earths core and mantle and triggered off Super Volcanism and subsequent Methane release from the oceans.
• Theory : Oxygen removal from both land and sea. Plus Hydrogen Sulfide toxicity.
• Theory : Rise and fall of gravity field.
• Theory: Extinction period came in 3 waves.
• Theory 1 : Meteorite Impact event in the super ocean Panthalassa or the East Antarctic Ice Sheet Crater (crater 300 miles wide), also crater at Bedout High seabed off Australia.
• Theory 2: Super volcanism. Massive flood basalt eruptions over thousands of years : Siberian Traps.
• Theory 3: Methane release over thousands of years from deep oceans after ocean temperatures rise by approx 5°C.
  Recorded changes to carbon isotopes.
• Advanced conifers.
• Reptiles, Dragonflies, Roaches, Beetles, Flies.
• Mammal-like reptiles.
• Fossils : Trilobites, mollusks, corals and brachiopods.
• Final assembly of Pangaea.
• Ice Age: Glaciers cover most of Gondwanaland.

• Climate change : glacial periods to warm.
• Early bark bearing trees including conifers
• Formation of coal deposits.
• Low sea levels, swamps and generally warm climate.
• Age of Plants. Flowerless spore-forming plants and ferns.
• Amphibians dominant : Large air breathing Insects and Amphibians inhabit Carboniferous swamps.
• 36% Higher oxygen content in the atmosphere than today, allowing arthropods to grow larger
• First Sharks and Reptiles.
• Mississippian: Earth Tectonic Movements produced Supercontinent : Pangea.

• Devonian-Carboniferous Mass Extinction transition series (lasting over 20Ma) ~ 70% of species lost.
• Devonian : Ammonites, marine animals, primitive air breathing fish evolved into the first tetrapods (amphibians).
• First forests.
• Terrestrial Arthropods: Includes Insects, Arachnids, Crustaceans and others.
• Age of Fish : Fossils Mainly marine animal life, jawed fish and invertebrates.

• Extinction event. Theories possibly caused by climate change, low sea levels due to glaciers, changes in ocean mixing and hyper salinity.
• Primitive vascular land plants.
• Moss forests, and first soils.
• Multi-cellular relatives of modern spiders and millipedes.
• Fish with jaws and air breathing animals.
• Trilobites abundant then generally in decline.
• Super continent : Gondwanaland.

• Ordovician-Silurian Transition. 85% of species lost. Two extinction events during the Ordovician, devastates marine and reef building organisms, including some Trilobites.
  Possible explanation: onset of glaciation and interglacial periods. Sea levels rose and fell.
• Early primitive jawless fish.

• Extinction event : Marked fall in carbon-13 isotope. Theory: due to a reduction in bacteria, temporarily out-competed by new multicelluar biomass organisms.
• Hard bodied shelly fauna: Arthropods known as Trilobites, and primitive reef-forming animals.
• Invertebrates dominant; worms, jellyfish, trilobites.
• Multi-celled life forms start to take hold.
  "ancient life"

Neoproterozoic (900 to 543 ma)
      Ediacaran (630 to 543 ma)
      Cryogenian (630-850ma)
      Tonian (850 to 1000 ma)

• First great extinction event : 70% of all organic lost.
  Radiation of acritarchs
  (possibly due to major impact event).
• Volcanic Activity released huge quantities of carbon dioxide and methane over 1,000+ years, Greenhouse effect ends Ice Age.
• Severe Ice Age (Snowball Earth/Cryogenian Period), ice sheets extend to equator.
• 750Ma Rhodinia super continent broke up.
• Multi-cellular life, including earliest animals.
• "visible life" Early shelled organisms.

• Explosion of bio diversity.
• Evolution of sexual reproduction.
• Accumulation of oxygen in the atmosphere.
• Formation of super continent : Rhodinia
• 1.5Ma Columbia super continent broke up.

• Cyanobacteria: Blue-green algae & Stromatolytes giving off oxygen lead to evolution of Earths early primitive oxidizing atmosphere.
• 2.5Ma Kenorland super continent broke up.
• Oxygen Catastrophe : atmosphere becomes poisonous to anaerobic bacteria.
  

Archeozic

Reducing Atmosphere

• "earlier life" earliest fossils : Stromatolytes start to produce oxygen as by product of early photosynthesis.
• Anaerobic single celled micro-organisms: bacteria & viruses flourish in Earths early reducing atmosphere.
• 2.8Ma super continent : Vaalbara broke up.

Hadean Era
(4600 to
3800 ma)

Azoic Time : No Atmosphere

Formation of the moon probably by giant impact. Largest hit Earth has ever suffered.

Planetary accretions during the formation of Solar System.
approx 4.6 to 3.8 Billion years ago.

• Azoic Rocks, (no organic life forms).
• 3.8 billion years : banded iron beds, Greenland.
• No atmosphere.
• Formation of Earths Crust.
• Zircon crystals date from 4440 Ma.
• Meteorite bombardment. Oldest meteorites found ~ 4.6 Billion Years Old.