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3
Quaternary Period 3 MYA- Present Time
At the start, continents were just about in the same place as they are today. The entire Quaternary period is considered an Ice Age because of Antarctica. -
66
Tertiary Period 66 MYA- 3 MYA
It spanned the transition between a globally very warm climate with relatively high sea levels and dominated by reptiles to a world of polar glaciation, very different zones of climate and mammalian dominance. -
145
Cretaceous Period 145 MYA- 66 MYA
Last portion of the "Age of Dinosaurs" but new dinosaurs were also introduced during this time. The breakup and dispersion of Pangea continued. -
200
Jurassic Period 200 MYA- 145 MYA
The supercontinent Pangea split apart. Many dinosaurs lived during this time, carnivores hunted down the herbivores. Oceans were full of fish, squid and coiled ammonites and other creatures. -
250
Triassic Period 250 MYA- 200 MYA
Some natural disaster (unsure on what it was) caused the extinction of over 90% of earth's species during this period. Following that event came a time of great change and rejuvenation. -
300
Permian Period 300 MYA- 250 MYA
The permian diversification of the early amniotes into the ancestral groups of the mammals, turtles, lepidosaurs, and archosaurs. The world during this period was dominated by two continents known as Pangea and Siberia surrounded by a global ocean called Panthalassa. -
360
Carboniferous Period 360 MYA-300 MYA
Famous for it's vast swamp forests. Such swamps produced the coal from which the term "Carboniferous", or "carbon-deriving", is derived. -
420
Devonian Period 420 MYA- 360 MYA
During this period, two major animal groups colonized the land. First, the tetrapods then the arthropods. There were three continental landmasses. North America and Europe were covered with water near the equator, a portion of Siberia lay to the North and a composite continent of South America, Africa, Antarctica, India and Australia dominated the Southern Hemisphere. -
440
Silurian Period 440 MYA- 416 MYA
Underwater life thrived during this period. Continental land masses were low and sea levels were rising which led to rich shallow sea ecosystems with new ecological niches. -
500
Ordovician Period 500 MYA-440 MYA
During this period, the area north of the tropics was almost entirely ocean and most of the world's land was collectively in the Southern supercontinent of Gondwana. -
570
Cambrian Period 570-500 MYA
Most major groups of animals first appear during this time period in the fossil record. This event is sometimes called the "Cambrian Explosion," because of the relatively short time over which this diversity of forms appears.
