In the Triassic Period, the first mammals appear, modern corals appear, and a type of dinosaur, the Archosaur, takes over. At the end of the Triassic Period though, there is an extinction that wipes out the Archosaurs and leaves a place for new dinosaurs to take over.
After the Permian Period, there was the Triassic Period, which was from 251 MYA to 199 MYA.
In the Jurassic Period, mammals are now common, but they are very small, as small as squirrels and mice. The very first birds and lizards are seen as well.
After the Triassic Period, there was the Jurassic Period, which was from 199 MYA to 145 MYA.
In the Cretaceous Period, we see the first flowering plants, the first modern sharks, the first marsupials, birds begin to replace pterodactyls, and the carbon dioxide was at modern day levels in the atmosphere. At the end of the Cretaceous Period, there is a major extinction where 75% of all species die out, and after, mammals and birds are the dominant land vertebrates
After the Jurassic Period, there was the Cretaceous Period, which was from 145 MYA to 65.5 MYA.
I know! It certainly is amazing! Now, lets talk about the relationship between the development of the atmosphere and the development of life on Earth. Let's see if you can figure it out.
Wow! I can't belive there was that much development over millions of years!
Well, at first there was no atm osphere, but eventually the atmosphere developed but it's composition consisted of deadly gases, and it wasn't to strong, like how it is today, and the sun's ultra violet radiation harmed the Earth.
Your doing great so far!
Soon though, the atmosphere grew stronger because a microorganism, cyanobacteria, used photosynthesis to produce oxygen. Eventually, the ozone layer and hydrogen, and the right amount of oxygen and close to the right amount of carbon dioxide all made up the composition of the atmosphere.
Don't forget, gravity also developed and helped keep the developing life on Earth on the ground!