The Cambrian Period

The Cambrian Period
Science
10/26/95
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. It¹s 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 Earth¹s 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.