FC: Precambrian time By Fahad Al Ruwayeh 7-2
1: Table of contents What is my Time line topic? 2 What was happening 4 Plant Life 6 Animal Life 8 Climate and time happened 10 Summary 12 Bibliography 14 | Precambrian time
2: My topic is the Precambrian time and it is the first geologic time ever.
4: What Happened? The Precambrian geologic time was the longest time ever in the history of Earth. It was about four billion years long! Scientists did not know much about the Precambrian time because they haven't found much evidence about it. But they found enough evidence for me to type this research. The Precambrian time was named after Cambria, Wales. It is a super eon divided into several eons that make the Precambrian time. The next period of time is the Cambrian period. Read more to find out what lives in the Precambrian time.
6: Plant Life Plants in the Precambrian time started from multi cellular life that looked like bacteria. The multi cellular life then began to evolve or develop into more complex organisms about a billion years later. Such plants that have evolved are green-blue algae, acritarches, angiosperms and modern reefs that live in the ocean in the modern days. All plants evolved from bacteria like organisms. Evidence of these organisms was found in fossils mostly in Greenland and Wales.
8: Animal Life The first complex multi cellular life forms seem to have appeared roughly 600 million years ago. The oldest fossil evidence of complex life comes from the Lantian formation, at least 580 million years ago. The Lantian formation is a 150 meter thick sequence of rocks deposited in southern China during a ninety million year epoch in the Ediacaran period. Its algae and really small fossils are oldest large and complex fossils known. A fairly unlike collection of soft-bodied forms is known from a mixture of locations worldwide between 542 and 600 million years ago. These are referred to as Ediacaran or Vendian biota. Hard-shelled creatures appeared toward the end of the Precambrian life span. Later, a very diverse fauna (all of the animal life of any particular region) appeared in a place called the Burgess Shale. The Burgess Shale formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields. It is famous for the preservation of the soft parts of its fossils. At 505 million years (Middle Cambrian) old, it is one of the earliest fossil beds containing soft-part prints. At the same time an explosion had occurred, which was the beginning of most animal life such as marine animals. This is called the Cambrian Explosion of Life during the early Cambrian life.
10: Time and Climate About four billion years ago to three billion years ago was the time of glaciations. During that period of time there was no oxygen, but there was life that could survive such as bacteria and multi cellular life. The temperature from that time was 30 degrees Celsius lower than today's temperature. About 2.4 billion years to 2.2 billion years ago, oxygen started to appear, and the ozone layer formed in the stratosphere. The Late Precambrian time from 750 to 600 million years ago and was the beginning of the global warming. When global warming finished 100 million years later, dinosaurs and marine animals started to appear, but now in modern times global warming is still continuing.
12: Conclusion 1. Oxygen appeared in the middle of the Precambrian time, that was about two billion years ago. 2. Global warming started 750 to 600 million years ago and ended 600 million years later. 3. The Precambrian time ended 452 million years ago. 4. Dinosaurs started to appear during the beginning of the Cambrian period of time, that was after the Precambrian. 5. More animals started to appear such as marine animals, as the same time dinosaurs appeared toward the end.
14: Bibliography Eriksson, P.G.. The Precambrian Earth: tempos and events. Amsterdam: Elsevier, 2004. Print "Precambrian." Wikipedia. Unknown ed. 2013. Print. "Precambrian Climate." University de catholique Louvain. N.p., 3 Aug. 2008. Web. 20 Feb. 2013. stratus.astr.ucl.be.