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Cambrian Period 570-500 Million Years Ago
During this period there were no land plants,but it is estimated that fungi, algae and possibly lichens covered the land. Trilobites also thrived. -
Ordovician Period 500-435 Million Years Ago
Pangaea was mainly underwater but was moving south. It is characterized by its diverse marine invertebrates including the graptolites, trilobites, and brachiopods. The Ordovician Period also had many red and green algae. -
Silurian Period 435-345 Million Years Ago
The Silurian Period was most famous for its climate change that it brought to the Earth, commonly known as the greenhouse effect. Many of Earths glaciers retracted back to the North and South Poles. -
Devonian Period 395-345 Million Years Ago
The Devonian period was a time of plant growth. This is where the first ferns were introduced. By the end of the Devonian, ferns, horsetails, and seed plants had also appeared. Also, land-living vertebrates flourished including wingless insects. -
Carboniferous 345-280 Million Years Ago
The Carboniferous Period was the first time the world ever saw freshwater clams and tetrapods that grew as big as alligators. Also, the South and North Poles were both completely covered in ice. -
Permian Period 280-225 Million Years Ago
The Permian period saw the largest extinction ever recorded in the history of life on Earth. Most marine invertebrates died out. On land, diapsids and synapsids also died, but made possible the life of the dinosaurs in the next time period. -
Triassic Period 225-195 Million Years Ago
The Triassic Period was a time of small life. Few plants and animals survived the mass extinction of the Permian Period. But those that did attempted at recovering from the deficit that they experienced. -
Jurassic Period 195-136 Million Years Ago
The Jurassic Period had dinosaurs. The bigger ones were herbivores while the smaller carnivores stalked their larger prey. Oceans were full of fish, squid, and coiled ammonites. Mammals started to fly. -
Cretaceous Period 136-65 Million Years Ago
The Cretaceous Period saw new life. The first flowering plants were born, as well as many insect groups, and many modern mammal and bird groups. Pangaea moved massively during this time period, creating very distinct floras and faunas between the Northern and Southern continents. -
Tertiary 65-1.8 Million Years Ago
The biggest change in the Tertiary Period was the demise of the dinosaurs. The Earth also significantly cooled down during this period. Mammals overcame reptiles as the dominant vertebrates. -
Quaternary Period
Glaciers retreated from the poles and then drew back. Mammals grew massive, grew fur, and then died out. At the beginning of the period, the continents were in about the same position that they are in today. The last ice age occured and sea levels went back to where they still remain today. The first humans walked the Earth and evolved into what they are today.
