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Article: Cambrian Explosion
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Cambrian Explosion
Scientists agree that the Cambrian explosion is one of the most significant events in the history of life. It is marked by a series of biological changes that took place over a relatively short period of geologic time during the early Cambrian, 543 to 520 million years ago. (The entire Cambrian period ranged from 543 to approximately 490 million years ago.) First and foremost, the Cambrian explosion is marked by the global appearance of organisms with skeletal hard parts in the fossil record in contrast to the strictly soft-bodied creatures prior to this. Initially, these skeletal structures were simple in design, such as minute cylindrical tubes, tiny cones, and ...