There was an event commonly known as the "oxygen crisis" which occurred around 2.4 billion years ago.
One theory suggests that this was caused due to the production of oxygen by micro organisms. In the early Earth this oxygen normally reacted with minerals in the surface rocks during weathering (creating very thick beds of oxidised rocks such as banded iron formations). However a point was reached where no more minerals were available to react with the oxygen and so it began to accumulate in the atmosphere.
The increase in oxygen proved catastrophic for a large proportion of life at the time leading to the mass extinction event described earlier.
For further information and to see some of the other theories as to the cause of the rapid increases in atmospheric oxygen concentration, please see the related link.
Studying the Precambrian time is challenging due to a lack of well-preserved rocks, limited fossil records, and the immense timescale involved (4.6 billion to 541 million years ago). Additionally, geological processes have altered many Precambrian rocks over time, making it hard to interpret their original characteristics accurately.
Precambrian time is another name for the group of eons that includes the Hadean, Archean, and Proterozoic eons.
The end of the Precambrian Eon is marked by the beginning of the Phanerozoic Eon, approximately 541 million years ago. This transition is characterized by a significant increase in the diversity of multicellular life forms and the appearance of abundant fossils in the geological record.
The Precambrian era spanned approximately 4 billion years, making it the longest geologic time period in Earth's history.
ok im going to start off by saying this, the last answerer is stupid, and doesnt know what he is talking about. it goes from: PERIOD ERA EPOCH there you go ;)
nope, it happened way after
Over most of Precambrian time 80 percent of earths history-the only life forms are bacteria ,which appear about 3,500 million years ago. multiple-cells marine animals like spriggina appear at the end of the era
what major change in life forms occured at the end of precambrain time
Over most of Precambrian time 80 percent of earths history-the only life forms are bacteria ,which appear about 3,500 million years ago. multiple-cells marine animals like spriggina appear at the end of the era
The Precambrian ended about 541 million years ago.
what major change in life forms occured at the end of precambrain time
It was the Precambrian time period.
what major change in life forms occured at the end of precambrain time
In Precambrian times, a relative shortage of volcanoes resulted in low emissions of carbon dioxide. This contributed to low surface temperature, and a lot of glaciers towards the end of the period.
Lady Gaga
Because it was created in the precambrian era...The Candadian Shield was formed in the Precambrian Era.The rocks of the Canadian Shield formed during the Precambrian time.
Because it was created in the precambrian era...The Candadian Shield was formed in the Precambrian Era.The rocks of the Canadian Shield formed during the Precambrian time.