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  2. Cambrian explosion - Wikipedia

    en.wikipedia.org/wiki/Cambrian_explosion

    The Cambrian explosion (also known as Cambrian radiation [1] or Cambrian diversification) is an interval of time beginning approximately in the Cambrian period of the early Paleozoic, when a sudden radiation of complex life occurred and practically all major animal phyla started appearing in the fossil record.

  3. Cambrian–Ordovician extinction event - Wikipedia

    en.wikipedia.org/wiki/Cambrian–Ordovician...

    It was preceded by the less-documented (but probably more extensive) End-Botomian mass extinction around 517 million years ago, and the Dresbachian extinction event about 502 million years ago. The Cambrian–Ordovician extinction event ended the Cambrian period, and led into the subsequent Ordovician period.

  4. Cambrian - Wikipedia

    en.wikipedia.org/wiki/Cambrian

    The Cambrian explosion was a period of rapid multicellular growth. Most animal life during the Cambrian was aquatic. Trilobites were once assumed to be the dominant life form at that time, [58] but this has proven to be incorrect. Arthropods were by far the most dominant animals in the ocean, but trilobites were only a minor part of the total ...

  5. Paleozoic - Wikipedia

    en.wikipedia.org/wiki/Paleozoic

    The Cambrian spanned from 539–485 million years ago and is the first period of the Paleozoic Era of the Phanerozoic. The Cambrian marked a boom in evolution in an event known as the Cambrian explosion in which the largest number of creatures evolved in any single period of the history of the Earth.

  6. Ordovician - Wikipedia

    en.wikipedia.org/wiki/Ordovician

    180 m; rising to 220 m in Caradoc and falling sharply to 140 m in end-Ordovician glaciations [8] The Ordovician ( / ɔːr d ə ˈ v ɪ ʃ i . ə n , - d oʊ -, - ˈ v ɪ ʃ ən / or-də- VISH -ee-ən, -⁠doh-, -⁠ VISH -ən ) [ 9 ] is a geologic period and system , the second of six periods of the Paleozoic Era , and the second of twelve ...

  7. Scientists Say Complex Life Is an Astounding 1.5 ... - AOL

    www.aol.com/scientists-complex-life-astounding-1...

    Although the Cambrian explosion is often touted as this amazing geologic event that kickstarted complex life on Earth (and it definitely is that), scientists know that multicellular life existed ...

  8. Extinction event - Wikipedia

    en.wikipedia.org/wiki/Extinction_event

    At the end of the Ediacaran and just before the Cambrian explosion, yet another Proterozoic extinction event (of unknown magnitude) is speculated to have ushered in the Phanerozoic. [ 5 ] 1

  9. Great Ordovician Biodiversification Event - Wikipedia

    en.wikipedia.org/wiki/Great_Ordovician_Bio...

    The Great Ordovician Biodiversification Event (GOBE) was an evolutionary radiation of animal life throughout [1] the Ordovician period, 40 million years after the Cambrian explosion, [2] whereby the distinctive Cambrian fauna fizzled out to be replaced with a Paleozoic fauna rich in suspension feeder and pelagic animals.