Eocene–Oligocene climate transition
E49688
The Eocene–Oligocene climate transition was a major global cooling event around 34 million years ago that marked the shift from a greenhouse to an icehouse Earth, including the formation of large Antarctic ice sheets.
All labels observed (6)
How this entity was disambiguated
This entity first appeared as the object of triple T391049 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Eocene–Oligocene climate transition Context triple: [Paleogene, contains, Eocene–Oligocene climate transition]
-
A.
On the Imperfection of the Geological Record
"On the Imperfection of the Geological Record" is a chapter in Charles Darwin's *On the Origin of Species* that addresses why the fossil record is incomplete and how this affects evidence for evolutionary change.
-
B.
Pliocene epoch
The Pliocene epoch was a geological time period roughly 5.3 to 2.6 million years ago marked by cooler global climates, the expansion of grasslands, and significant evolutionary developments among mammals and early hominins.
-
C.
Great American Biotic Interchange between North and South America
The Great American Biotic Interchange between North and South America was a major paleozoogeographic event in which land and freshwater animals migrated between the two continents after the formation of the Isthmus of Panama, profoundly reshaping their ecosystems and faunas.
-
D.
Evolving Planet
Evolving Planet is a permanent exhibition at Chicago’s Field Museum that traces the history of life on Earth, from its origins through the age of dinosaurs to the present.
-
E.
Anthropocene
The Anthropocene is a proposed geological epoch characterized by the dominant global impact of human activities on Earth's climate, ecosystems, and geology.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Eocene–Oligocene climate transition Target entity description: The Eocene–Oligocene climate transition was a major global cooling event around 34 million years ago that marked the shift from a greenhouse to an icehouse Earth, including the formation of large Antarctic ice sheets.
-
A.
On the Imperfection of the Geological Record
"On the Imperfection of the Geological Record" is a chapter in Charles Darwin's *On the Origin of Species* that addresses why the fossil record is incomplete and how this affects evidence for evolutionary change.
-
B.
Pliocene epoch
The Pliocene epoch was a geological time period roughly 5.3 to 2.6 million years ago marked by cooler global climates, the expansion of grasslands, and significant evolutionary developments among mammals and early hominins.
-
C.
Great American Biotic Interchange between North and South America
The Great American Biotic Interchange between North and South America was a major paleozoogeographic event in which land and freshwater animals migrated between the two continents after the formation of the Isthmus of Panama, profoundly reshaping their ecosystems and faunas.
-
D.
Evolving Planet
Evolving Planet is a permanent exhibition at Chicago’s Field Museum that traces the history of life on Earth, from its origins through the age of dinosaurs to the present.
-
E.
Anthropocene
The Anthropocene is a proposed geological epoch characterized by the dominant global impact of human activities on Earth's climate, ecosystems, and geology.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
Cenozoic climate transition
ⓘ
global cooling event ⓘ paleoclimatic event ⓘ |
| alsoKnownAs |
EOT
ⓘ
Eocene–Oligocene climate transition ⓘ
surface form:
Eocene–Oligocene boundary event
Eocene–Oligocene climate transition ⓘ
surface form:
Eocene–Oligocene transition
|
| associatedWith |
Eocene–Oligocene climate transition
self-linksurface differs
ⓘ
surface form:
Eocene–Oligocene extinction events
expansion of grasslands in some regions ⓘ turnover in mammalian faunas ⓘ |
| characterizedBy |
changes in atmospheric CO2 levels
ⓘ
changes in ocean circulation ⓘ global cooling ⓘ growth of Antarctic ice sheets ⓘ rapid temperature drop ⓘ shift from greenhouse to icehouse climate state ⓘ |
| endTime | early Oligocene epoch ⓘ |
| followedBy | Oligocene icehouse climate state ⓘ |
| hasCause |
Antarctic isolation by circumpolar currents
ⓘ
decline in atmospheric CO2 concentration ⓘ opening of Southern Ocean gateways ⓘ tectonic reorganization ⓘ |
| hasEffect |
changes in marine biodiversity
ⓘ
changes in terrestrial ecosystems ⓘ cooling of deep oceans ⓘ expansion of Antarctic ice sheets ⓘ onset of large-scale Antarctic glaciation ⓘ reorganization of atmospheric circulation ⓘ reorganization of ocean circulation patterns ⓘ sea-level fall due to ice-sheet growth ⓘ strengthening of equator-to-pole temperature gradients ⓘ |
| locationOfEffect |
Antarctica
ⓘ
Southern Ocean ⓘ deep ocean basins ⓘ global climate system ⓘ |
| occursAtTime | Eocene–Oligocene boundary ⓘ |
| partOf |
Cenozoic
ⓘ
surface form:
Cenozoic Era
Paleogene ⓘ
surface form:
Paleogene Period
|
| precededBy | Eocene greenhouse climate state ⓘ |
| separates |
Paleogene
ⓘ
surface form:
Eocene Epoch
Oligocene Epoch ⓘ |
| significance |
established persistent polar ice sheets on Earth
ⓘ
major step in long-term Cenozoic cooling trend ⓘ |
| startTime | approximately 34 million years ago ⓘ |
| studiedUsing |
benthic foraminifera isotopes
ⓘ
deep-sea oxygen isotope records ⓘ marine sediment cores ⓘ paleobotanical data ⓘ terrestrial sedimentary records ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Eocene–Oligocene climate transition Description of subject: The Eocene–Oligocene climate transition was a major global cooling event around 34 million years ago that marked the shift from a greenhouse to an icehouse Earth, including the formation of large Antarctic ice sheets.
Referenced by (7)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Eocene–Oligocene transition
this entity surface form:
Eocene–Oligocene boundary event
Eocene–Oligocene climate transition
→
associatedWith
→
Eocene–Oligocene climate transition
self-linksurface differs
ⓘ
this entity surface form:
Eocene–Oligocene extinction events
this entity surface form:
Eocene–Oligocene glaciation
this entity surface form:
Paleogene (Eocene–Oligocene) extinction events