Eras De La Tierra

Since the beginning of times, the earth has experienced different changes in many aspects like unicellular and multi cellular organisms, animals, starting with the first jaw fishes and finishing withus, and it also has changed in the plants, some creatures were created by evolution and others got extinct and the paleontologists classify them in different ages starting from the Hadean to theCenozoic age.


The Hadean (4.6 to 4 billion years ago) was the first non official age, its name was inspired in "hades" the underworld god from the Greek mythology, and it was the edge where theentire world was covered on fire and volcanoes exploding all the time everything was just ashes and hardened lava. As I said before it is a non official age because there are little proves that ithappened.

Then it was the Achaean age (1.5 billion years ago), where the life started with the first prokaryotic cells
After the Achaean it was the Proterozoic age (2.5 to 1.6 billion years ago), wheresome bacterial were originated and the first plants emerged.

Our fourth age was the Paleozoic era (542 million years ago to 251 million years ago); it was divided in sub-levels such as:-Cambrian: where it was the cambric explosion, the aquatic life started and it was a quick diversification of the living beings.
-Ordovician: multi cellular living beings invaded the ocean.
-Silurian: thefirst jawed fishes appeared. It is said the first jawed fishes because the jaw was what made the difference between them and the other bacterial creatures.
-Devonian: the ocean animal life, manage toget out of the water to the dry land.
-Carboniferous: the first reptiles appeared.

-Permian: reproductive membranes appeared and the continents got together to form what we called "Pangea".With the “Pangea”, the new edge began, what we call the Mesozoic era (251 to 199.6 million years ago), it was also divided in other stages.

-Triassic: the first mammals and the dinosaurs appeared....