The+Cambrian+Period+by+iam...

[|The Cambrian Period] 544-490 Million Years Ago. = Introduction = The [|Earth] during the Cambrian period, also known as "The Cambrian Explosion" had many new events happening. Before the Cambrian period was the [|Pre-Cambrian] era which lasted from 4.6 billion years ago to 543 million years ago. This was the longest [|era] in the history of Earth. In this period the Earth formed and life appeared. Unicellular animals such as [|bacteria] appeared. Also a new life form, jellies, appeared. Following the Cambrian period was the [|Ordovician] period which lasted from 490-438 million years ago. In this period invertebrates continue to dominate the world. [|Trilobites] prosper. Towards the middle of this period an ice age starts and there is a mass extinction. [|Glaciers] cover most of the super-continent Gondwanaland. Sixty percent of all life on earth went extinct in this period. Over all, before and after the Cambrian period the world was extremely different than it was during the Cambrian period. = [|Plate Tectonics] = For hundreds of millions of years underground plates and continents have been moving. 544 to 490 million years ago, during the Cambrian period, most of the continents were under the equator. Gondwana and modern day India, Africa and Australia were centered in the South Pole. The super-continent Laurentia also known as Laurasia was closer to the equator. Imagine, the land that we now know as sub-freezing Antarctica, was hot, tropical and sunny.

Massachusetts was located in the super-continent Laurentia. It would have had a climate similar to modern day Brazil because it was moving closer to the equator. Throughout the entire Cambrian period all the continents had warm climates. All of the oceans, where the ** only ** life on Earth was, would have been warm and clean. Other small, warm shallow seas made by melting ice sheets, covered most of the land and ancient organisms prospered. Over all, all land that humans now live on was on or under the equator and everything above it was ocean. Massachusetts had a tropical climate, as it was near the equator. Most of the planet had a warm climate. = Abiotic = The Cambrian period had a variety of rocks and landforms. There are not many places in the world where you can find Cambrian rocks exposed above ground, simply because it was so long ago. Two main places where you can find them are the U.K. and the [|Burgess Shale] in the Canadian Rockies. The continents were extremely different 544 million years ago. There were three main continents. Baltica included what are now Northern Europe, Ireland and Scotland. Laurentia included modern day North America. Gondwana, the largest continent, centered in the South pole had modern day Africa and Australia. Warm, clear oceans covered most of the world at this time. There were many fossils from the Cambrian Period. The place where most of these were found was the Burgess Shale in the Canadian Rockies. This is a huge spot where fossils and some animals were found perfectly preserved because calcium carbonate (CaCo3) a natural substance helped maintain them undamaged. One type of fossil found was a[| mollusk]. These invertebrates were abundant in the oceans. Another fossil was [|brachiopod], a shelled invertebrate. One of the most rare fossils was [|paradoxides], a trilobite. In all, the Cambrian Period has left us many fossils and traces to help us understand how the world was millions of years ago. = Biotic = Although most animals from the Cambrian period are extinct, many people still regard this period as the most important point in the history of life, because of all the new animals that appeared. 544-490 million years ago invertebrates dominated the ocean. The only plants in the world were single and multi-celular [|green algae].Sometimes these would come together and look like a bigger plant such as seaweed or kelp but it was actually just many algae living in close proximity. One of the most prosperous species was trilobite, a segmented animal with a hard exo-skeleton. Another group of animals that thrived was shelled invertebrates such as mollusks, clams and brachiopods. Many soft bodied organisms such asjellies had an easy life, for they had no predators yet. [|Sponges] lived in the warm oceans covering our planet. This period is known by many as “The Cambrian Explosion” because this was a relatively short period of time where an incredible amount of new life appeared. One new animal that appeared was [|anomalocaris]. This was most likely the first large predator and carnivore. It fed on smaller trilobites and organisms. Another new type of animal that appeared was [|marine arthropods]. These would eventually evolve into dominant insects and spiders. Possibly one of the most important new life forms was the early fish haikuichthys. Fish had never lived before this period. Haikuichthys was tremendously important in the history of human evolution. This was the first vertebrate; it had a very primitive backbone. In hundreds of millions of years this would evolve to be the "blueprint" for the human skeleton.



Two websites you can go to to learn more about the Cambrian period are:[|PBS Evolution Library] and [|National Geographic]

To see my visuals bibliography click here To see my links bibliography click here To see my research bibliography click here

To see a paragraph reflecting on this project, click here

To hear a great song about the "//**Cambrian Explosion**//",written by __John Palmer__ and performed by __Brighter Lights, Thicker Glasses__ [|click here]

