Cenozoic
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Cenozoic
The Cenozoic (also Caenozoic or Cainozoic) Era () (, meaning "new life" (Greek (kainos), "new", and (zoe), "life"), is the most recent of the three classic geological eras and covers the period from 65.5 million years ago to the present. It is marked by the Cretaceous?Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and the end of the Mesozoic Era. The Cenozoic era is ongoing.
SubdivisionThe Cenozoic is divided into two periods, the Paleogene and Neogene, and they are in turn divided into epochs. The Paleogene consists of the Paleocene, Eocene, and Oligocene epochs, and the Neogene consists of the Miocene, Pliocene, Pleistocene, and Holocene epochs, the last of which is ongoing. Historically, the Cenozoic has been divided into periods (or sub-eras) named the Tertiary (Paleocene through Pliocene) and Quaternary (Pleistocene and Holocene). TectonicsGeologically, the Cenozoic is the era when the continents moved into their current positions. Australia-New Guinea split from Gondwana and drifted north and, eventually, adjacent to South-east Asia; Antarctica moved into its current position over the South Pole; the Atlantic Ocean widened and, later in the era, South America became attached to North America. India collided with Asia between 55 and 45 million years ago; Arabia collided with Eurasia, closing the Tethys ocean, around .[1] ClimateThe Cenozoic has been a period of long-term cooling. In the early Cenozoic, particulate ejecta from the K-T boundary impact blocked incoming solar radiation . After the tectonic creation of Drake Passage, when Australia fully detached from Antarctica during the Oligocene, the climate cooled significantly due to the advent of the Antarctic Circumpolar Current which brought cool deep Antarctic water to the surface. Warm conditions returned in the Miocene due to uncovered gas hydrates releasing carbon dioxide. When South America became attached to North America creating the Isthmus of Panama, the Arctic region cooled due to the strengthening of the Humboldt and Gulf Stream currents, eventually leading to the Last Glacial Maximum. LifeThe Cenozoic is the age of new life. During the Cenozoic, mammals diverged from a few small, simple, generalized forms into a diverse collection of terrestrial, marine, and flying animals. The Cenozoic is just as much the age of savannas, or the age of co-dependent flowering plants and insects. Birds also evolved substantially in the Cenozoic. Monte Bolca is an important lagerstätte near Verona, Italy, containing excellently preserved fish and other fossils of Eocene age.
See also
ReferencesBibliography
ar:???? ????????? ast:Cenozoicu bs:Kenozoik br:Senozoeg bg:?????? ca:Cenozoic cs:Kenozoikum da:Kænozoikum de:Känozoikum et:Kainosoikum es:Era Cenozoica eo:Kenozoiko fa:??????? fr:Cénozoïque ko:??? hr:Kenozoik id:Kenozoikum is:Nýlífsöld it:Cenozoico he:?????????? kk:???????? la:Aera Caenozoica lt:Kainozojus hu:Kainozoikum nl:Cenozoïcum ja:??? no:Kenozoikum nn:Kenozoikum nds:Känozoikum pl:Kenozoik pt:Cenozóico ro:Neozoic ru:???????? sk:Kenozoikum sr:???????? sh:Kenozoik fi:Kenotsooinen maailmankausi sv:Kenozoikum vi:??i Tân sinh tr:Senozoik uk:???????????? ??? zh:??? Source: Wikipedia | The above article is available under the GNU FDL. | Edit this article
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