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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.
They probably represent changes on a global scale, and as such may help to constrain possible causes of the Cambrian explosion. The chemical signature may be related to continental break-up, the end of a "global glaciation", or a catastrophic drop in productivity caused by a mass extinction just before the beginning of the Cambrian.
As understanding of the events of the Cambrian becomes clearer, data have accumulated to make some postulated causes for the Cambrian explosion look improbable. Some examples are the evolution of herbivory, vast changes in plate tectonic rates or orbital motion, or different evolutionary mechanisms in force.
One hypothesis that unifies this evidence links these environmental changes to widespread volcanic eruptions caused by the emplacement of the Kalkarindji Large Igneous Province or LIP. [ 13 ] [ 14 ] [ 15 ] These widespread eruptions would have injected large amounts of greenhouse gases into the atmosphere causing warming of the climate and ...
Around the same geologic period of Snowball Earth (it is debated if it was the cause or the result of Snowball Earth), the Great Oxygenation Event (GOE) was occurring. The event known as the Cambrian Explosion followed and produced the beginnings of populous bilateral organisms, as well as a greater diversity and mobility in multicellular life ...
Volcanic activity, particularly that of large igneous provinces, has been speculated to have been the cause of the environmental crisis. [3] The emplacement of the Namaqualand–Garies dykes in South Africa has been dated to 485 mya, the time at which the Cambrian–Ordovician extinction event occurred, although there remains no unambiguous evidence of a causal relationship between this ...
The resulting sediments supplied to the ocean would be high in nutrients such as phosphorus, which combined with the abundance of CO 2 would trigger a cyanobacteria population explosion, which would cause a relatively rapid reoxygenation of the atmosphere and may have contributed to the rise of the Ediacaran biota and the subsequent Cambrian ...
It is not known what caused the excursion. [7] The Shuram excursion may have played a role in sparking the rise of animals that resulted later in the Cambrian explosion. [8] The oxygen-consuming Ediacara biota experienced a radiation during the isotopic excursion as a response to the transient surplus of oxidants. [9]