FACTOID # 22: South Dakota has the highest employment ratio in America, but the lowest median earnings of full-time male employees.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Oligocene" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Oligocene

The Oligocene epoch is a geologic period of time that extends from about 34 million to 23 million years before the present. As with other older geologic periods, the rock beds that define the period are well identified, but the exact dates of the start and end of the period are slightly uncertain. The name Oligocene comes from the Greek oligos (few) and ceno (new) and refers to the sparsity of additional modern mammalian faunas after a burst of evolution during the Eocene. The Oligocene follows the Eocene epoch and is followed by the Miocene epoch. The Oligocene is the third and final epoch of the Palaeogene period. A division of geologic time less than a period and greater than an age. ... The geologic time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of the Earth. ... Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Eutheria (includes extinct ancestors)/Placentalia (excludes extinct ancestors) Afrosoricida Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata (extinct) Perissodactyla Pholidota Plesiadapiformes... A speculative phylogenetic tree of all living things, based on rRNA gene data, showing the separation of the three domains, bacteria, archaea, and eukaryotes. ... The Eocene epoch (56-34 Ma) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. ... The Eocene epoch (56-34 Ma) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. ... The Miocene epoch is a period of time that extends from about 23 to 5. ... Palaeogene (alternatively Paleogene) period is a unit of geologic time that began 65 and ended 23 million years ago. ...


The Oligocene is often considered an important time of transition, a link between "[the] archaic world of the tropical Eocene and the more modern-looking ecosystems of the Miocene."(1) In ecology, the word ecosystem is an abbreviation of the term, ecological system. ...


The start of the Oligocene is marked by a major extinction event that may be related to the impact of large extraterrestrial object in Siberia and/or near Chesapeake Bay. The Oligocene-Miocene boundary is not set at an easily identified worldwide event but rather at regional boundaries between the warmer Oligocene and the relatively cooler Miocene. An extinction event (also extinction-level event, ELE) occurs when a large number of species die out in a relatively short period of time. ... Siberia Siberia (Russian: , common English transliterations: Sibir’, Sibir; from the Tatar for “sleeping land”) is a vast region of Russia and northern Kazakhstan constituting almost all of northern Asia. ... Chesapeake Bay - Landsat photo The Chesapeake Bay is the largest estuary in the United States. ...

Tertiary sub-era
Paleogene period
Paleocene epoch Eocene epoch Oligocene epoch
Danian Selandian Ypresian Lutetian Rupelian Chattian
Thanetian Bartonian Priabonian

Contents

The Tertiary period was previously one of the major divisions of the geologic timescale, from the end of the Cretaceous period about 65 million years ago to the start of the Quaternary period about 1. ... Paleogene (alternatively Palaeogene) period is a unit of geologic time that began 65 and ended 23 million years ago. ... The Paleocene epoch (65-56 MYA) (early dawn of the recent) is the first geologic epoch of the Palaeogene period in the modern Cenozoic era. ... The Eocene epoch (56-34 Ma) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. ... The Danian (also known as the Montian) is the first stage of the Paleocene Epoch. ... Selandian is a stage of the middle Paleocene Epoch. ... The Ypresian is the first stage of the Eocene Epoch. ... The Lutetian is a stage of the middle Eocene Epoch. ... The Rupelian (also known as Stampian, Tongrian, Latdorfian, or Vicksburgian) is the first of two stages of the Oligocene Epoch. ... The Chattian (also known as Chickasawhayan) is the second and final of two stages of the Oligocene Epoch. ... The Thanetian (also known as the Landenian or the Heersian) is the last stage of the Paleocene Epoch. ... In the geologic timescale, the Bartonian is the age of the Eocene epoch of the Paleogene period of the Cenozoic era of the Fanerozoic eon that is comprehended between 40 million 400 thousand and 37 million 200 thousand years ago, approximatedly. ... The Priabonian (also known as Jacksonian or Runangan) is the final stage of the Eocene Epoch. ...


Oligocene Subdivisions

Oligocene faunal stages from youngest to oldest are: Faunal stages are a subdivision of geologic time used primarily by paleontologists who study fossils rather than by geologists who study rock formations. ...

Chattian (28.4 ± 0.1 – 23.03 MYA)
Rupelian (33.9 ± 0.1 – 28.4 ± 0.1 MYA)

The Chattian (also known as Chickasawhayan) is the second and final of two stages of the Oligocene Epoch. ... In astronomy, geology, and paleontology, mya is an acronym for million years ago and is used as a unit of time to denote length of time before the present. ... The Rupelian (also known as Stampian, Tongrian, Latdorfian, or Vicksburgian) is the first of two stages of the Oligocene Epoch. ...

Oligocene Climate

Climates remained warm, although the slow global cooling that eventualty led to the Pleistocene glaciations started around the end of the epoch. The Pleistocene Epoch is part of the geologic timescale. ... Glaciation, often called an ice age, is a geological phenomenon in which massive ice sheets form in the Arctic and Antarctic and advance toward the equator. ...


See also: PaleoMap Project: Oligocene


Oligocene Paleogeography

During this period, the continents continued to drift toward their present positions. Antarctica continued to become more isolated, and finally developed a permanent ice cap.(2) Portrayal of shifting continents The concept of continental drift was first proposed by Alfred Wegener. ... An ice cap is a dome-shaped water ice mass that covers less than 50,000 km² of land area (usually covering a highland area). ...


Mountain building in western North America continued, and the Alps started to rise in Europe as the African plate continued to push north into the Eurasian plate. A brief marine incursion marks the early Oligocene in Europe. Oligocene marine exposures are rare in North America. There appears to have been a land bridge in the early Oligocene between North America and Europe as the faunas of the two regions are very similar. Orogeny is the process of mountain building, and as such is both a tectonic structural event, a geographical event and a chronological event, in that orogenic events happen within a time frame, affect certain regions of rocks and crust, and cause distinctive structural phenomena and related tectonic activity. ... World map showing North America A satellite composite image of North America. ... The West face of the Petit Dru above the Chamonix valley near the Mer de Glace. ... For other uses, see Europe (disambiguation). ... The African plate is shown in pinkish-orange on this map The African Plate (sometimes referred to as the Nubian Plate) is a continental tectonic plate covering the continent of Africa and extending westward to the Mid-Atlantic Ridge. ... The Eurasian plate is shown in green on this map. ... Fauna is a collective term for animal life. ...


Oligocene Flora

Angiosperms continued their expansion throughout the world; tropical and sub-tropical forests were replaced by temperate deciduous woodlands. Open plains and deserts became more common.(3) Grasses expanded from the water-bank habitat in the Eocene, and moved out into open tracts; however even at the end of the period it was not quite common enough for modern savanna.(4) A grassy swamp. ... Savanna is a grassland dotted with trees, and occurs in several types of biomes. ...


In North America, subtropical species dominated with cashews and lychee trees present, and temperate trees such as roses, beech and pine common. The legumes of the pea and bean family spread, and sedges, bulrushes and ferns continued their ascent. Binomial name Anacardium occidentale L. The Cashew (Anacardium occidentale) is a tree in the flowering plant family Anacardiaceae. ... Binomial name Litchi chinensis Sonn. ... Species About 100, see text A rose is a flowering shrub of the genus Rosa and the flower of this shrub. ... Species Fagus crenata - Japanese Beech Fagus engleriana - Chinese Beech Fagus grandifolia - American Beech Fagus hayatae - Taiwan Beech Fagus japonica - Japanese Blue Beech Fagus longipetiolata - South Chinese Beech Fagus lucida - Shining Beech Fagus mexicana - Mexican Beech or Haya Fagus orientalis - Oriental Beech Fagus sylvatica - European Beech Beech (Fagus) is a genus... Species About 115. ... Varieties of soybean seeds, a popular legume A flowering legume (Lupin) The term legume has two closely related meanings in botany, a situation encountered with many botanical common names of useful plants whereby an applied name can refer to either the plant itself, or to the edible fruit (or useful... Genera See text The family Cyperaceae, or the Sedge family, is a taxon of monocot flowering plants that superficially resemble grasses or rushes. ... The term bulrush (or sometimes as bullrush) typically refers to tall, herbaceous plants that grow in wetlands. ... Classes Marattiopsida Osmundopsida Gleicheniopsida Pteridopsida A fern, or pteridophyte, is any one of a group of some twenty thousand species of plants classified in the Division Pteridophyta, formerly known as Filicophyta. ...


Oligocene Fauna

Important Oligocene land faunas are found on all continents except Australia. More open landscapes allowed animals to grow to larger sizes than they had earlier in the Paleogene.(5) Marine faunas became fairly modern, as did terrestrial vertebrate faunas in the northern continents. This was probably more as a result of older forms dying out than as a result of more modern forms evolving. Subgroups †Conodonta Hyperoartia   Petromyzontidae (lampreys) †Pteraspidomorphi †Thelodonti †Anaspida †Cephalaspidomorphi   †Galeaspida   †Pituriaspida   †Osteostraci Gnathostomata (jawed vertebrates)   †Placodermi   Chondrichthyes (cartilaginous fish)   †Acanthodii   Osteichthyes (bony fish)     Actinopterygii (ray-finned fish)     Sarcopterygii (lobe-finned fish)       Actinistia (coelacanths)       Dipnoi (lungfish)       Tetrapoda (four-limbed vertebrates)         Amphibia (amphibians)         Amniota (amniotic embryo)           Sauropsida (reptiles)             Aves (birds)           Synapsida (mammal...


South America was apparently isolated from the other continents and evolved a quite distinct fauna during the Oligocene. South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ...


Mammals

Brontotherium Indricotherium Enteledont Hyaenodon


Reptiles

Birds

Sea Life

bivalves


Oligocene Oceans

Oceans continued to cool, particularly around Antarctica.


Reference

(1)Tim Haines, Walking with Beasts: A Prehistoric Safari, (New York: Dorling Kindersley Publishing, Inc., 1999), p. 104.


(2) Ibid.


(3) Ibid.


(4) Ibid.


(5) Ibid.


External link


  Results from FactBites:
 
Oligocene - Wikipedia, the free encyclopedia (562 words)
The Oligocene follows the Eocene epoch and is followed by the Miocene epoch.
The Oligocene is the third and final epoch of the Palaeogene period.
The start of the Oligocene is marked by a major extinction event that may be related to the impact of large extraterrestrial object in Siberia and/or near Chesapeake Bay.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m