BC: Bibliography: | 1. http://www.ucmp.berkeley.edu/cambrian/cambrian.php 2. http://science.nationalgeographic.com/science/prehistoric-world/cambrian/ 3. http://www.fossils-facts-and-finds.com/cambrian_period.html | I dedicate this book to ms.Moore ,Sabah, abdulhameed, and hamad. | The end
FC: Abdulaziz Al Baghli march,17,2013 7-2
1: My topic is the Cambrian period in the Paleozoic era, which was part of the Phanerozoic eon. | Table of contents: | Topic: | Page: | Time Plants Animals Climate Summary Bibliography and dedications | 2-5 6-9 10-13 14-17 18-21 Back cover.
2: The Cambrian Period occurred from 490 to 543 million years ago.
4: During the time of the Cambrian period many important events occurred like the evolution of protection (spikes,hard shells,and scales) on some sea living animals.Also during the time of the Cambrian period; advancing glaciers dropped the waters temperature killing off the organisms that cant adapt. | During the time of the Cambrian period:
6: Plants during the Cambrian period: | There were not many plants during the Cambrian period; the most common were two types of simple algae. These types of algae included the coralline red algae and the dasyclod green algae. Some kinds of algae such as the coralline red algae and dasyclod green algae move closer to their kind. By coming close together they look like some kind of plant.
8: Plants during the Cambrian period: | It is a very controversial theory that plants such as seaweed grew or existed during the Cambrian period. It is not a sure bet that microscopic plants such as seaweed evolved in the Cambrian period because it is absent in the fossil record. Summing it up, the plants that existed during the Cambrian period were the two kinds of algae and perhaps seaweed
11: Animals during the Cambrian period: | Most of the life forms that lived during the Cambrian period lived in water.Many of them had no backbones which made them invertebrates. One of the invertebrates that lived in the water was the trilobite which was an arthropod. It got its name from the three lobes on its skin. The trilobite was also one of the first animals with eyesight. 100 types of trilobites existed.
13: Animals during the Cambrian period: | There were plenty of other species living during the Cambrian period. These species did not have backbones. These invertebrates were mollusks, worms, and echinoderms These invertebrates once filled the Cambrian seas. A wiwaxia is another animal that had scales and spikes. This shows the range of animals in the Cambrian seas, from backbone less sponges to the trilobites to the wiwaxia with its scales and spikes it uses for protection.
15: Climate during the Cambrian period: | The climate at the beginning of the Cambrian period was cold but over time the climate in all parts of the earth grew warmer. World climates were mild but there was no glaciation. Most of North America lay in warm southern tropical and temperate latitudes which supported the growth of extensive shallow water reefs. Advancing glaciers dropped the waters temperature which killed the non-adapting organisms.
16: The climate during the Cambrian period: | There were high atmospheric carbon dioxide levels in the Cambrian period. The carbon dioxide levels were fifteen times greater than the ones in modern times. Changes in the climate also played a lead role in the Cambrian periods mass extinction.
18: The summary of the Cambrian period: | The Cambrian period started off as the explosion of life because of all the creatures that evolved during that time and ended in mass extinction because the advancing glaciers dropped the waters temperature killing all of the life forms that could not adapt to the waters temperature leading to mass extinction.
20: The summary of the Cambrian period: | There were many invertebrates that lived in the oceans during the Cambrian period. Some of them had hard shells, spikes, or scales for protection. The wiwaxia is an example of an animal with spikes on the dorsal side of its body. Even with this kind of protection the wiwaxia had a soft underbelly.