AskDefine | Define Cenozoic

Dictionary Definition

Cenozoic n : approximately the last 63 million years [syn: Cenozoic era, Age of Mammals]

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English

Pronunciation

Adjective

  1. of a geologic era within the Phanerozoic eon and comprises the Paleogene and Neogene periods from about 65 million years ago to the present, when the continents moved to their current position and modern plants and animals evolved

Noun

Cenozoic
  1. the Cenozoic era

See also

Extensive Definition

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. It covers the 65.5 million years since the Cretaceous–Tertiary extinction event at the end of the Cretaceous that marked the demise of the last non-avian dinosaurs and the end of the Mesozoic Era. The Cenozoic era is ongoing.

Subdivision

The 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).

Tectonics

Geologically, 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 .

Climate

The 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.

Life

The 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.

References

Bibliography

  • British Caenozoic Fossils, 1975, The Natural History Museum, London.
  • Geologic Time, by Henry Roberts.
Cenozoic in Arabic: حقبة السينوزوي
Cenozoic in Asturian: Cenozoicu
Cenozoic in Bosnian: Kenozoik
Cenozoic in Breton: Senozoeg
Cenozoic in Bulgarian: Ценозой
Cenozoic in Catalan: Cenozoic
Cenozoic in Czech: Kenozoikum
Cenozoic in Danish: Kænozoikum
Cenozoic in German: Känozoikum
Cenozoic in Estonian: Kainosoikum
Cenozoic in Spanish: Era Cenozoica
Cenozoic in Esperanto: Kenozoiko
Cenozoic in Persian: نوزیستی
Cenozoic in French: Cénozoïque
Cenozoic in Korean: 신생대
Cenozoic in Croatian: Kenozoik
Cenozoic in Indonesian: Kenozoikum
Cenozoic in Icelandic: Nýlífsöld
Cenozoic in Italian: Cenozoico
Cenozoic in Hebrew: קנוזואיקון
Cenozoic in Kazakh: Кайнозой
Cenozoic in Latin: Aera Caenozoica
Cenozoic in Lithuanian: Kainozojus
Cenozoic in Hungarian: Kainozoikum
Cenozoic in Dutch: Cenozoïcum
Cenozoic in Japanese: 新生代
Cenozoic in Norwegian: Kenozoikum
Cenozoic in Low German: Känozoikum
Cenozoic in Polish: Era kenozoiczna
Cenozoic in Portuguese: Cenozóico
Cenozoic in Romanian: Neozoic
Cenozoic in Russian: Кайнозой
Cenozoic in Slovak: Kenozoikum
Cenozoic in Serbian: Кенозоик
Cenozoic in Serbo-Croatian: Kenozoik
Cenozoic in Finnish: Kenotsooinen maailmankausi
Cenozoic in Swedish: Kenozoikum
Cenozoic in Vietnamese: Đại Tân sinh
Cenozoic in Turkish: Senozoik
Cenozoic in Ukrainian: Кайнозойська ера
Cenozoic in Chinese: 新生代
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