Paleontology Thread

[Samsid]

Discuss any part of the history of planet earth in this thread.

[Malotun]

You should really share that pre-written material that you said, i'm not really into paleontology but I would like to read it to learn some new things.

[Samsid]

I will post it when it's converted

[Samsid]

I will make a chronological list with descriptions of all the geological time periods. In this post I will be describing the Precambrian eons.

Hadean:
Hadean is the very first eon. It's official beginning was during the creation of earth, 4.567 billion years ago. Hadean lasted for 537 million years, until 4030. However the age makes it difficult to find information, so Hadean is not divided into different eras. Hadean is mostly characterised by extreme temperatures, high volcanism, a partially molten surface and frequent collisions with other solar system bodies, one of which is believed to have formed the moon. Around 4.4 billion years ago, major collision stopped (not forever though, see LHB) and stones and rocks began forming as most of the earths surface had hardened from being molten.

Archean:
The Archean is the next oldest time period and stretches from 4,0 billion years ago to 2,5 billion years ago. Archean is divided into four eras: Eoarchean, Paleoarchean, Mesoarchean and Neoarchean. At the beginning of Archean, Earth had cooled significantly and even allowed for an atmosphere and oceans. The surface continued to harden and was now entirely solid. The oldest rocks ever found on Earth were from Archean. During the Archean, significant chemical development took place in the atmosphere and the conditions for life were created in the form of hydrogen, carbon and nitrogen, but also methane, water vapor and ammonia. However, the extreme amounts of volcanic eruptions meant that carbon dioxide and nitrogen were dominant in the atmosphere. From the end of this eon there are fossil findings of stromatolites and early prokaryotic life forms,  but the latter was likely dominant as species.

Proterozoic:
The Proterozoic eon took place 2500 million years ago to 541 million years ago. During Proterozoicum, the early development of life occurred with the appearance of bacteria and algae. It has also been shown that photosynthesis occurred during this period of Earths history. The development of an oxygen-rich atmosphere was vital for the Cambrian explosion. It is divided into three eras: the Paleoproterozoic, Mesoproterozoic, and Neoproterozoic. This eon also saw several glaciations, possibly leading to the theoretical Snowball earth. It is also believed that during this eon, several smaller continents crashed into eachother, creating the first supercontinent, called Columbia (however this process repeated itself and no clear supercontinent was formed as they usually broke apart after a while)

To be continued...

[Big_Appa]

Love it.

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