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Introduction:
Old of 4.6 billion years, the Earth underwent several major periods, called geological eras: Precambrian, Paleozoic, the Mesozoic, the Cenozoic. Its history is marked by the appearance of life and its evolution, marked by phases of colonization of the seas and the continents by plants and then by animals but also marked by serious crises.
A succession of crisis:
Plant life conquered the land surface 450 million years ago, in fact the Earth's atmosphere became rich enough in oxygen and the ozone layer was sufficient: thus during the Devonian (from 410 to 360 million years ago) mosses and ferns grew up.
Then at Carboniferous Times, the climate in Europe was tropical and forests and swamps were omnipresent (which will allow the formation of coal). Amphibians and reptiles grew up.
Everything seems to be fine but do not forget to take into account the crises that the Earth will suffer: at the end of the Primary Age, a lot of marine species disappeared completely and continental fauna and flora were also strongly damaged.
What is the cause of this major crisis called Permian Crisis (250 million years ago)?
It is not a single cause but a combination of several geological factors that caused this crisis: a major marine regression occurred at the end of the Permian and climate changed abruptly because of the grouping of continents. So a big part of the seas disappeared and a continental climate and a volcanism appeared.
But then the Secondary Age saw the golden age of dinosaurs and ammonites; more than 600 to 700 species of dinosaurs reigned during million of years on the Earth until the Cretaceous Crisis at Tertiary Age.
65 million years ago, a brutal and massive extinction of dinosaurs and ammonites occurred.
As the Permian Crisis, the Cretaceous Crisis was caused by the combination of several phenomena: collision of an asteroid with the Earth, intense volcanic activity and new climatic changes associated with a marine regression.
Humanity will appear after: from 2 to 3 million years ago with Homo Habilis.
Reminder on "Earthcaches": There is no container or logbook on the given coordinates. Just visit the site and answer the questions by e-mail.There is no need to wait for my reply, feel free to log immediately after. If the answers are incorrect, I will let you know. Happy caching!
To validate your visit:
1-. What percentage of marine species was destroyed during the Permian Crisis?
2-. Give two examples of mammals who survived to the Cretaceous Crisis
3-. What is the other group with mammals who survived to the Cretaceous Crisis?
4-. What are the 3 different types of fossils which are represented in the information board of the Cretaceous Crisis?
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