Cenozoic

The Cenozoic (also Caenozoic or Cainozoic) Era (pronEng|ˌsiːnəˈzoʊɪk/, /ˌsɛn-) (meaning "new life" (Greek Polytonic|καινός ("kainos"), "new", and Polytonic|ζωή ("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.

ubdivision

The Cenozoic Era 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.Clarifyme|the continents have been moving to their current position since their formation...|date=March 2008 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 Ma|35.cite doi|10.1016/j.palaeo.2008.04.021 ]

Climate

The Cenozoic Era has been a period of long-term cooling. In the early Cenozoic, particulate ejecta from the K-T boundary impact blocked incoming solar radiation Fact|date=December 2007. 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.Fact|date=November 2007 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 currentsFact|date=December 2007, eventually leading to the Last Glacial Maximum.

Life

The Cenozoic Era 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.

ee also

*Geologic Time Scale
*K-T Boundary

References

Bibliography

*"British Caenozoic Fossils", 1975, The Natural History Museum, London.
*"Geologic Time", by Henry Roberts.


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Look at other dictionaries:

  • cenozoic — CENOZÓIC subst., adj. (geol.) Neozoic. [pr.: zo ic] – Din fr. cenozoïque. Trimis de valeriu, 13.09.2007. Sursa: DEX 98  cenozóic adj. m. (sil. zo ic), pl. cenozóici; …   Dicționar Român

  • Cenozoic — [sē΄nə zō′ik, sen΄əzō′ik] adj. [ceno (< Gr kainos: see CENE) + ZOIC] [sometimes c ] designating or of the third geologic era of the Phanerozoic Eon, usually subdivided into the Tertiary and Quaternary periods and characterized by the… …   English World dictionary

  • Cenozoic — Ce no*zo ic, a. [Gr. ? recent + ? life.] (Geol.) Belonging to the most recent division of geological time, including the tertiary, or Age of mammals, and the Quaternary, or Age of man. [Written also {c[ae]nozoic}, {cainozoic}, {kainozoic}.] See… …   The Collaborative International Dictionary of English

  • Cenozoic — 1854, Cainozoic, from Gk. kainos new, fresh, recent, novel (see RECENT (Cf. recent)) + zoon animal (see VITAL (Cf. vital)). The era that began with the demise of the dinosaurs and the rise of recent species …   Etymology dictionary

  • Cenozoic — (also Cainozoic) ► ADJECTIVE Geology ▪ of or relating to the era following the Mesozoic era (from about 65 million years ago to the present). ORIGIN from Greek kainos new + z ion animal …   English terms dictionary

  • Cenozoic — adjective Etymology: Greek kainos + English zoic Date: 1841 of, relating to, or being an era of geological history that extends from the beginning of the Tertiary period to the present time and is marked by a rapid evolution of mammals and birds… …   New Collegiate Dictionary

  • Cenozoic — /see neuh zoh ik, sen euh /, Geol. adj. 1. noting or pertaining to the present era, beginning 65 million years ago and characterized by the ascendancy of mammals. See table under geologic time. n. 2. the Cenozoic Era or group of systems. Also,… …   Universalium

  • Cenozoic — 1. adjective Of a geologic era within the Phanerozoic eon comprising the Paleogene and Neogene from about 65 million years ago to the present, when the continents moved to their current position and modern plants and animals evolved. 2. noun …   Wiktionary

  • cenozoic — adj. pertaining to the Cenozoic era (most recent geological era) n. Cainozoic, most recent geological era …   English contemporary dictionary

  • Cenozoic — Ce•no•zo•ic [[t]ˌsi nəˈzoʊ ɪk, ˌsɛn ə [/t]] adj. 1) gel noting or pertaining to the present era, beginning 65 million years ago, characterized by the ascendancy of mammals See geologic time 2) gel the Cenozoic Era or group of systems • Etymology …   From formal English to slang

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