Era 2: The Paleozoic Era

• Cambrian Period (541 to 485.4 MYA)- In the Cambrian Period, the first period of the Paleozoic Era, there was an “explosion” of new animals. We call it the “Cambrian Explosion”. 

• Ordovician Period (485.4 to 443.8 MYA)- A series of plate collisions resulted in formation of the supercontinent “Pangea” (which means, “all land”)

• Silurian Period (443.8 to 419.2 MYA)- There was a big diversification of fish including the jawless and the jawed. Also, the atmosphere developed more ozone.  

• Devonian Period (419.2 to 358.9 MYA) - Two of the most important parts of the DP were the emergence of the first insects and also the first forests, seeds and soil. 

• Carboniferous Period (359.2 to 299 MYA)- In North America, sufficient differentiation between the rock forms allows for 2 subperiods to be labeled: Mississippian Period and Pennsylvanian Period. During The Mississippian Period the amphibians first appeared and began to diversify.  During the Pennsylvanian Period the first reptiles appeared and began to diversify. 

• Permian Period (298.9 to 251.9 MYA)- The Greatest Mass Extinction Event of All Time (the “great dying”)- The marine and terrestrial lifeforms nearly died out because greenhouse gas levels increased to extreme levels due to climate change, caused in part by high volcanic activity!