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c. 4,533 Ma – Hadean Eon, Precambrian Supereon and unofficial Cryptic era start as the Earth–Moon system forms, possibly as a result of a glancing collision between proto-Earth and the hypothetical protoplanet Theia (the Earth was considerably smaller than now, before this impact). This impact vaporized a large amount of the crust, and sent ...
The Precambrian is an informal unit of geologic time, [3] subdivided into three eons (Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga ) to the beginning of the Cambrian Period, about 538.8 million years ago ( Ma ), when hard-shelled creatures first appeared in ...
An era is the second largest geochronologic time unit and is equivalent to a chronostratigraphic erathem. [ 14 ] [ 13 ] There are ten defined eras: the Eoarchean , Paleoarchean , Mesoarchean , Neoarchean , Paleoproterozoic , Mesoproterozoic , Neoproterozoic , Paleozoic , Mesozoic and Cenozoic , with none from the Hadean eon.
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 Cenozoic is just as much the age of savannas, the age of co-dependent flowering plants and insects, and the age of birds. [40] Grasses also played a very important role in this era, shaping the evolution of the birds and mammals that fed on them. One group that diversified significantly in the Cenozoic as well were the snakes.
It consists of three eras: The Paleozoic, Mesozoic, and Cenozoic, [105] and is the time when multi-cellular life greatly diversified into almost all the organisms known today. [147] The Paleozoic ("old life") era was the first and longest era of the Phanerozoic eon, lasting from 538.8 to 251.9 Ma. [105]
End of Mesozoic era start of the Cenozoic era and the Paleogene period, Paleocene epoch (66–56 Ma) Evidence for grasses in dinosaur dung . Tyrannosaurus rex. Earliest species of Triceratops. Quetzalcoatlus, one of the largest flying animals, appears. Crocodiles. Madagascar breaks away from India. Bolide creates Chicxulub Crater.
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 ...