• WordNet 3.6
    • n Oligocene from 40 million to 25 million years ago; appearance of sabertoothed cats
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Webster's Revised Unabridged Dictionary
    • a Oligocene (Geol) Of, pertaining to, or designating, certain strata which occupy an intermediate position between the Eocene and Miocene periods.
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Century Dictionary and Cyclopedia
    • Oligocene In geology, a division of the Tertiary series, including groups formerly classed in part as Upper Eocene and in part as Lower Miocene. The rocks classed as Oligocene are partly of fresh-water and brackish origin, and partly marine. They are especially well developed in the Paris basin, in northern Germany (where this name was first proposed by Beyrich), and in Switzerland. The important formation known as the Molasse belongs partly to the Oligocene. The vegetation of that period was varied and interesting, and indicative of a decidedly warmer climate than that at present prevailing. Beds referred to the Oligocene extend from Florida through to Texas, and are characterized by the presence of Orbiloides mantelli, a widely distributed foraminifer.
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Chambers's Twentieth Century Dictionary
    • adj Oligocene ol′i-gō-sēn (geol.) pertaining to a division of the Tertiary series, the rocks chiefly of fresh and brackish water origin, with intercalations of marine beds.
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Webster's Revised Unabridged Dictionary
Oligo-, + Gr. new, recent
Chambers's Twentieth Century Dictionary
Gr. oligos, little, kainos, new.


In literature:

That you and I exist today must be due to the preparedness of some shaggy anthropoid of the Oligocene.
"Jungle Tales of Tarzan" by Edgar Rice Burroughs
The Tertiary Era is divided by geologists into four periods: the Eocene, Oligocene, Miocene, and Pliocene.
"The Story of Evolution" by Joseph McCabe
The genus Mesohippus, of the middle Oligocene, may be selected as a kind of half-way stage in the long progression.
"Darwin and Modern Science" by A.C. Seward and Others
Sirmur Series - Oligocene.
"The Birth-Time of the World and Other Scientific Essays" by J. (John) Joly
Middle Oligocene, N. America.
"The Outline of Science, Vol. 1 (of 4)" by J. Arthur Thomson
Again, in the Hampshire Basin and Isle of Wight, Eocene and Oligocene formations rest upon the Chalk.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 4" by Various
Remains of several of the existing genera have been found in Oligocene and later beds of Europe, Sumatra and North America.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 4" by Various
Remains of centipedes closely related to existing forms have been recorded from Oligocene beds.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 6" by Various
During the upper Oligocene time very nearly the whole island was undoubtedly submerged.
"The History of Cuba, vol. 1" by Willis Fletcher Johnson
The Oligocene only occur in the Hampshire basin, the higher strata only in the Isle of Wight.
"The Geological Story of the Isle of Wight" by J. Cecil Hughes
Hallux vestigial or absent since Oligocene.
"Encyclopaedia Britannica, 11th Edition, Volume 3, Slice 7" by Various
The Oligocene division has been generally accepted as a distinct period, but "Paleocene" is not so widely used.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 6" by Various
The Oligocene is generally marine.
"Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 7" by Various
The latter, like the similar deposits in other West Indian islands, is probably of Oligocene age.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7" by Various
Several forms occur in the Oligocene and Miocene beds of Europe.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8" by Various
The genus is Oligocene.
"The Cambridge Natural History, Vol X., Mammalia" by Frank Evers Beddard
Shrews are also known from the Lower Oligocene upwards both in the eastern and western hemispheres.
"Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 6" by Various
Both lineages likely had an earlier history extending back to their divergence in the Oligocene.
"Evolution and Classification of the Pocket Gophers of the Subfamily Geomyinae" by Robert J. Russell
Upon this foundation rests unconformably a series of marls and limestones of Eocene and early Oligocene age.
"Encyclopaedia Britannica, 11th Edition, Volume 15, Slice 2" by Various

In news:

The operation, in partnership with state owned Turkiye Petrolleri AO, was designed to test noncommercial gas shows in tight Oligocene Mezardere sands at 12,000 ft.