Geological Timeline

By xenon54xenon54
  • 3801 BCE

    Dating Method

    In order to not break the timeline, I put the dates in terms of millions of years rather than on a one for one basis, which would, again, break the timeline.
  • Period: 3800 BCE to 543 BCE

    Precambrian

    The biggest eon in Earth's history. It is the time in which life is forming. The Earth is nothing like what it is now, and from the oceans of this primordial earth will rise our Universal Common Ancestors.
  • Period: 3800 BCE to 2500 BCE

    Archean Era

    The era of the oldest life on Earth. It is from this era that life started and developed.
  • Period: 2500 BCE to 543

    Proterozoic Era

    The true Precambrian era. This is immediately before the Cambrian Explosion, and life is now beginning to diversify. Life is still prokaryotic but has clearly progressed from complex proteins in microscopic fatty micelles.
  • Period: 543 BCE to 1 BCE

    Phanerozoic Eon

    The time after the Cambrian Explosion. The eon of complex life. This was when complicated multi-cellular life began and flourished. We currently live in this eon.
  • Period: 543 BCE to 248 BCE

    Paleozoic Era

    The era of Old Life. This was immediately after the Cambrian Explosion and saw the greatest diversity of life ever before, with the first marine organisms and terrestrial plants.
  • Period: 543 BCE to 490 BCE

    Cambrian Period

    This is the period of the Cambrian Explosion and the first complex life has come. Life is mostly in the seas.
  • Period: 490 BCE to 443 BCE

    Ordovician Period

    Multi cellular life got vertebrae in this period with fish, the first true vertebrates. The Great Ordovician Bio-diversification Event further increased biodiversity.
  • Period: 443 BCE to 417 BCE

    Silurian Period

    The diversification of bony and jawed fish was the main evolutionary milestone for this period. Terrestrial life started, but was not successful until the Devonian.
  • Period: 417 BCE to 354 BCE

    Devonian Period

    In this age fish greatly diversified. Sharks, rays, and mollusks arose, and trilobites were still around. Tetrapods began to evolve to walk on land.
  • Period: 354 BCE to 290 BCE

    Carboniferous Period

    In this period, arthropods became substantially larger than what they are now due to exceptional atmospheric oxygen content. Amphibians and plants were the only two other forms of terrestrial life. Trees were essentially mosses and ferns since woody stems had not yet become widely populating.​
  • Period: 290 BCE to 248 BCE

    Permian Period

    The Permian is known for the rise of mammals and other advanced amniotes. It is also known for a catastrophic global event called the Great Dying, or P-Tr extinction event. 96% of all marine species went extinct, along with 70% of all terrestrial species. The ecosystem took 10 million years to recover. What exactly caused this near-death experience for life as we know it lies between volcanic activity, a meteor strike, microbes, and geography.
  • Period: 248 BCE to 65 BCE

    Mesozoic Era

    The age of the dinosaurs. In this era, dinosaurs of all shapes and sizes ruled the Earth for ~183,000,000 years. All mammals exist as rodents. This era will end with a mass extinction event likely caused by an asteroid or comet impact that killed most life on Earth.
  • Period: 248 BCE to 206 BCE

    Triassic Period

    The Triassic Period was primarily a rebuilding era resulting from the mass extinction at the end of the Permian. It saw the dinosaurs evolve, along with mammals, tortoises, and other biological families. Pangaea was a desert supercontinent at the beginning, but became more humid as it split into Laurasia and Gondwana.
  • Period: 206 BCE to 144 BCE

    Jurassic Period

    This period saw the spread and proliferation of dinosaurs across the globe. This was, truly, the period of the dinosaurs, and was the stereotypical age of the dinosaurs. Atmospheric carbon dioxide was seven times pre-industrial times.
  • Period: 144 BCE to 65 BCE

    Cretaceous Period

    This period saw the end of the dinosaurs and was also the longest period of the Mesozoic era. Most of the best-known dinosaurs were alive during this time, like Tyrannosaurus Rex. This period ended with a probable asteroid impact that killed 75% of species on Earth, almost on par with the P-Tr extinction event. Needless to say, the end was very bad for Earth. Again.
  • Period: 65 BCE to 1 BCE

    Cenozoic Era

    The current era in which humans exist. This era is also considered the era of Mammals, because it is the era in which they proliferated and took over the planet, just like the dinosaurs.