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During the Cambrian Period a lot of things happened both geologically and biologically.
The Cambrian Period was the first period of the Paleozoic Era, it lasted from 570
million years ago to 500 million years ago, 70 million years. It's very important because
it corresponds with the firs t appearance of abundant fossils especially Trilobites,
which characterizes a succeeding point in time. During the Cambrian Period the lapetus
Ocean appeared, the predecessor of the Atlantic Ocean, which separated the young North
American and Eurasian continents. Also Gondwanaland was in the final stages of
development. Gondwanaland was a very large continent made up of what is now South
America, Africa, Arabia, Madagascar, India, Australia, and Antarctica. Large shelled
organisms first emerged during the Cambrian. Also Earth's atmosphere contained the same
amount of oxygen as it does now, enough to sustain the metabolic rate of a complex
organism. Running down the middle of the North American continent was a large inland
sea called the Saulk sea. Inhabiting this sea, and the other seas of the primitive
world, were Trilobites and Brachiopods . Trilobites were three - lobed arthropods,
unlike other arthropods Trilobites had primitive ,unspecialized appendages.
Brachiopods are simple bi- valve shellfish that resemble clams. During the Cambrian
corals and chrinoids emerged. Chrinoids are sea animals of the class chrinoidea like
the sea lily and the feather star. The only plant life of the Cambrian period were
primitive algae.
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