Cambrian Period was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon.
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12 Facts About Cambrian
2.
The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells.
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3.
Cambrian marked a profound change in life on Earth: prior to the Cambrian, the majority of living organisms on the whole were small, unicellular and simple .
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4.
The rapid diversification of lifeforms in the Cambrian, known as the Cambrian explosion, produced the first representatives of all modern animal phyla.
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5.
Cambrian Period followed the Ediacaran Period and was followed by the Ordovician Period.
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6.
The use of Treptichnus pedum, a reference ichnofossil to mark the lower boundary of the Cambrian, is problematic because very similar trace fossils belonging to the Treptichnids group are found well below T pedum in Namibia, Spain and Newfoundland, and possibly in the western USA.
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7.
The Cambrian is divided into several regional faunal stages of which the Russian-Kazakhian system is most used in international parlance:.
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8.
Lower boundary of the Cambrian was originally held to represent the first appearance of complex life, represented by trilobites.
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9.
In Baltoscandia a Lower Cambrian transgression transformed large swathes of the Sub-Cambrian peneplain into an epicontinental sea.
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10.
The later half of Cambrian was surprisingly barren and showed evidence of several rapid extinction events; the stromatolites which had been replaced by reef building sponges known as Archaeocyatha, returned once more as the archaeocyathids became extinct.
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11.
Some Cambrian organisms ventured onto land, producing the trace fossils Protichnites and Climactichnites.
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12.
In contrast to later periods, the Cambrian fauna was somewhat restricted; free-floating organisms were rare, with the majority living on or close to the sea floor; and mineralizing animals were rarer than in future periods, in part due to the unfavourable ocean chemistry.
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