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The Precambrian (/ p r i ˈ k æ m b r i. ə n,-ˈ k eɪ m-/ pree-KAM-bree-ən, -KAYM-; [2] or Pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is ...
The Cambrian is the first period of the Paleozoic Era and ran from 539 million to 485 million years ago. The Cambrian sparked a rapid expansion in the diversity of animals, in an event known as the Cambrian explosion , during which the greatest number of animal body plans evolved in a single period in the history of Earth.
The Precambrian includes approximately 90% of geologic time. It extends from 4.6 billion years ago to the beginning of the Cambrian Period (about 539 Ma).It includes the first three of the four eons of Earth's prehistory (the Hadean, Archean and Proterozoic) and precedes the Phanerozoic eon.
The definition of standardised ... Proterozoic and Phanerozoic. [2] An era is the second ... the time before the Cambrian is often referred to as the Precambrian ...
The succeeding eon is the Phanerozoic, divided into three eras: the Palaeozoic, an era of arthropods, fishes, and the first life on land; the Mesozoic, which spanned the rise, reign, and climactic extinction of the non-avian dinosaurs; and the Cenozoic, which saw the rise of mammals. Recognizable humans emerged at most 2 million years ago, a ...
The Phanerozoic eon began following the Precambrian. The first major unit of time it contained was the Cambrian period of the Paleozoic era. [6] At the time, Earth's continents were in a very different arrangement and were generally smaller than they are today.
Aravalli-Delhi Orogen – Precambrian; Altaid Orogeny – Paleozoic Era; Uralian orogeny – Long series of linear deformation and mountain building events that raised the Ural Mountains during the Permian Period; Cimmerian and Cathaysian orogenies Active through Triassic and Jurassic Periods along south and southeast Asia. Dabie-Sulu orogeny ...
c. 538.8 ± 0.6 Ma – beginning of the Cambrian Period, the Paleozoic Era and the current Phanerozoic Eon. End of the Ediacaran Period, the Proterozoic Eon and the Precambrian Supereon. The Ediacaran fauna disappears, while the Cambrian explosion initiates the emergence of most forms of complex life, including vertebrates ( fish ), arthropods ...