Eocene–Oligocene extinction event

Grande CoupureEocene-Oligocene Boundaryat about the same timeboundaryEocene-OligoceneEocene-Oligocene extinction eventEocene-Oligocene transitionEocene–OligoceneEocene–Oligocene climatic deteriorationextinction event
The transition between the end of the Eocene (33.9 Ma) and the beginning of the Oligocene is marked by large-scale extinction and floral and faunal turnover (although minor in comparison to the largest mass extinctions).wikipedia
68 Related Articles

Eocene

Late EoceneMiddle EoceneEocene Epoch
The transition between the end of the Eocene (33.9 Ma) and the beginning of the Oligocene is marked by large-scale extinction and floral and faunal turnover (although minor in comparison to the largest mass extinctions).
The end is set at a major extinction event called the Grande Coupure (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay.

Oligocene

Late OligoceneOligocene epochEarly Oligocene
The transition between the end of the Eocene (33.9 Ma) and the beginning of the Oligocene is marked by large-scale extinction and floral and faunal turnover (although minor in comparison to the largest mass extinctions).
The start of the Oligocene is marked by a notable extinction event called the Grande Coupure; it featured the replacement of European fauna with Asian fauna, except for the endemic rodent and marsupial families.

Popigai crater

PopigaiPopigai diamondsPopigay crater
Another speculation points to several large meteorite impacts near this time, including those of the Chesapeake Bay crater and the Popigai crater of central Siberia, which scattered debris perhaps as far as Europe.
It is conjectured that it may have influenced the Eocene–Oligocene extinction event.

Palaeotheriidae

palaeotherepaleotherepalaeotheres
:"Pre-Grande Coupure faunas are dominated by the perissodact family Palaeotheriidae (distant horse relatives), six families of artiodactyls (cloven-hoofed mammals) (Anoplotheriidae, Xiphodontidae, Choeropotamidae, Cebochoeridae, Dichobunidae and Amphimerycidae), the rodent family Pseudosciuridae, the primate families Omomyidae and Adapidae, and the archontan family Nyctitheriidae.
Evidence suggests that the palaeotheriidae went extinct in Eurasia during the Early Oligocene, approximately 33 Ma, as part of a faunal turnover event known as the Grande Coupure.

Chesapeake Bay impact crater

Chesapeake BayChesapeake Bay craterChesapeake Bay Impact Structure
Another speculation points to several large meteorite impacts near this time, including those of the Chesapeake Bay crater and the Popigai crater of central Siberia, which scattered debris perhaps as far as Europe.

Year

myaMay
The transition between the end of the Eocene (33.9 Ma) and the beginning of the Oligocene is marked by large-scale extinction and floral and faunal turnover (although minor in comparison to the largest mass extinctions).

Extinction event

mass extinctionmass extinctionsextinction events
The transition between the end of the Eocene (33.9 Ma) and the beginning of the Oligocene is marked by large-scale extinction and floral and faunal turnover (although minor in comparison to the largest mass extinctions).

Cetacea

cetaceancetaceanswhales
They included the last of the ancient cetaceans, the Archaeoceti.

Archaeoceti

early whalearchaeocetearchaeocetes
They included the last of the ancient cetaceans, the Archaeoceti.

Global warming

climate changeglobal climate changeanthropogenic climate change
This was a time of major climatic change, especially cooling, not clearly caused by any single major impact or volcanic event.

Volcano

volcanicvolcanoesvolcanic igneous activity
This was a time of major climatic change, especially cooling, not clearly caused by any single major impact or volcanic event.

Meteorite

meteoritesmeteoriticmeteoric
Another speculation points to several large meteorite impacts near this time, including those of the Chesapeake Bay crater and the Popigai crater of central Siberia, which scattered debris perhaps as far as Europe.

Siberia

SiberianEastern SiberiaEast Siberia
Another speculation points to several large meteorite impacts near this time, including those of the Chesapeake Bay crater and the Popigai crater of central Siberia, which scattered debris perhaps as far as Europe.

Carbon dioxide

CO 2 CO2carbon dioxide (CO 2 )
A leading model of climate cooling at this time predicts a decrease in atmospheric carbon dioxide, which slowly declined in the mid to late Eocene and possibly reached some threshold approximately 34 million years ago.

Isotopes of oxygen

oxygen isotopeoxygen isotopesoxygen-15
This boundary is closely linked with the Oligocene Oi-1 event, an oxygen isotope excursion that marks the beginning of ice sheet coverage on Antarctica.

Ice sheet

ice sheetscontinental glacierice-sheet
This boundary is closely linked with the Oligocene Oi-1 event, an oxygen isotope excursion that marks the beginning of ice sheet coverage on Antarctica.

Priabonian

MP 17HeadonianPriabonian stage
The Grande Coupure, or "great break" in continuity, with a major European turnover in mammalian fauna about 33.5 Ma, marks the end of the last phase of Eocene assemblages, the Priabonian, and the arrival in Europe of Asian species.

Allopatric speciation

allopatricvicarianceallopatry
The Grande Coupure is characterized by widespread extinctions and allopatric speciation in small isolated relict populations.

Relict (biology)

relictrelict speciesrelicts
The Grande Coupure is characterized by widespread extinctions and allopatric speciation in small isolated relict populations.

Switzerland

SwissSwiss ConfederationSWI
It was given its name in 1910 by the Swiss palaeontologist Hans Georg Stehlin, to characterise the dramatic turnover of European mammalian fauna, which he placed at the Eocene-Oligocene boundary.

Hans Georg Stehlin

Stehlin
It was given its name in 1910 by the Swiss palaeontologist Hans Georg Stehlin, to characterise the dramatic turnover of European mammalian fauna, which he placed at the Eocene-Oligocene boundary.

Endemism

endemicendemic speciesendemics
The Grande Coupure marks a break between endemic European faunas before the break and mixed faunas with a strong Asian component afterwards.

Horse

horsesracehorseEquus caballus
:"Pre-Grande Coupure faunas are dominated by the perissodact family Palaeotheriidae (distant horse relatives), six families of artiodactyls (cloven-hoofed mammals) (Anoplotheriidae, Xiphodontidae, Choeropotamidae, Cebochoeridae, Dichobunidae and Amphimerycidae), the rodent family Pseudosciuridae, the primate families Omomyidae and Adapidae, and the archontan family Nyctitheriidae.

Anoplotheriidae

anoplotheriid
:"Pre-Grande Coupure faunas are dominated by the perissodact family Palaeotheriidae (distant horse relatives), six families of artiodactyls (cloven-hoofed mammals) (Anoplotheriidae, Xiphodontidae, Choeropotamidae, Cebochoeridae, Dichobunidae and Amphimerycidae), the rodent family Pseudosciuridae, the primate families Omomyidae and Adapidae, and the archontan family Nyctitheriidae.

Xiphodontidae

Xiphodontoideaxiphodont
:"Pre-Grande Coupure faunas are dominated by the perissodact family Palaeotheriidae (distant horse relatives), six families of artiodactyls (cloven-hoofed mammals) (Anoplotheriidae, Xiphodontidae, Choeropotamidae, Cebochoeridae, Dichobunidae and Amphimerycidae), the rodent family Pseudosciuridae, the primate families Omomyidae and Adapidae, and the archontan family Nyctitheriidae.