Cretaceous–Paleogene boundary
E6899
The Cretaceous–Paleogene boundary marks the geological transition 66 million years ago associated with a mass extinction event that wiped out non-avian dinosaurs and many other species, likely triggered by a large asteroid impact.
All labels observed (9)
How this entity was disambiguated
This entity first appeared as the object of triple T72256 — 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: Cretaceous–Paleogene boundary Context triple: [Cretaceous, hasBoundaryEvent, Cretaceous–Paleogene boundary]
-
A.
Cretaceous
The Cretaceous was the final period of the Mesozoic Era, marked by high sea levels, diverse dinosaurs, and ending with the mass extinction that wiped them out about 66 million years ago.
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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.
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C.
Deccan Traps volcanism
Deccan Traps volcanism refers to one of Earth’s largest known volcanic flood basalt events in western India, linked to mass extinction and major climatic changes near the end of the Cretaceous period.
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D.
Jurassic
Jurassic is a geologic period of the Mesozoic Era known for its abundant dinosaurs and the breakup of the supercontinent Pangaea.
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E.
The Endangered Earth
The Endangered Earth is the collective representation of the planet’s environmental crisis, recognized by Time as a symbolic “Person of the Year” to highlight global ecological threats and the urgency of conservation.
- 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: Cretaceous–Paleogene boundary Target entity description: The Cretaceous–Paleogene boundary marks the geological transition 66 million years ago associated with a mass extinction event that wiped out non-avian dinosaurs and many other species, likely triggered by a large asteroid impact.
-
A.
Cretaceous
The Cretaceous was the final period of the Mesozoic Era, marked by high sea levels, diverse dinosaurs, and ending with the mass extinction that wiped them out about 66 million years ago.
-
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.
Deccan Traps volcanism
Deccan Traps volcanism refers to one of Earth’s largest known volcanic flood basalt events in western India, linked to mass extinction and major climatic changes near the end of the Cretaceous period.
-
D.
Jurassic
Jurassic is a geologic period of the Mesozoic Era known for its abundant dinosaurs and the breakup of the supercontinent Pangaea.
-
E.
The Endangered Earth
The Endangered Earth is the collective representation of the planet’s environmental crisis, recognized by Time as a symbolic “Person of the Year” to highlight global ecological threats and the urgency of conservation.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
chronostratigraphic boundary
ⓘ
geological boundary ⓘ mass extinction boundary ⓘ |
| age | about 66 million years ago ⓘ |
| alsoKnownAs |
Cretaceous–Paleogene boundary
ⓘ
surface form:
K–Pg boundary
Cretaceous–Paleogene boundary ⓘ
surface form:
K–T boundary
|
| associatedWith |
Cretaceous–Paleogene boundary
self-linksurface differs
ⓘ
surface form:
Cretaceous–Paleogene extinction event
extinction of ammonites ⓘ extinction of many marine reptiles ⓘ extinction of many plankton species ⓘ extinction of many terrestrial plant species ⓘ mass extinction of non-avian dinosaurs ⓘ |
| cause | large asteroid impact ⓘ |
| characterizedBy |
abrupt faunal turnover
ⓘ
abrupt floral turnover ⓘ negative carbon isotope excursion in some sections ⓘ |
| correlatesWith | Chicxulub impact crater ⓘ |
| definedBy |
first appearance of Paleogene fossils above boundary
ⓘ
last appearance of many Cretaceous taxa below boundary ⓘ |
| evidence |
global iridium-rich clay layer
ⓘ
microtektites ⓘ shocked quartz ⓘ spherules from impact ejecta ⓘ |
| formerlyKnownAs |
Cretaceous–Paleogene boundary
self-linksurface differs
ⓘ
surface form:
Cretaceous–Tertiary boundary
|
| globalExtent | worldwide ⓘ |
| impactOn |
evolution of mammals
ⓘ
radiation of birds ⓘ restructuring of marine ecosystems ⓘ restructuring of terrestrial ecosystems ⓘ |
| linkedTo |
short-term global cooling followed by warming
ⓘ
sudden collapse of primary productivity in surface oceans ⓘ wildfires on a global or near-global scale ⓘ |
| locatedInTimeScale | International Chronostratigraphic Chart ⓘ |
| marksBeginningOf |
Cenozoic
ⓘ
surface form:
Cenozoic Era
|
| marksEndOf | Mesozoic Era ⓘ |
| marksTransitionBetween |
Cretaceous
ⓘ
surface form:
Cretaceous Period
Paleogene ⓘ
surface form:
Paleogene Period
|
| ratifiedBy | International Commission on Stratigraphy ⓘ |
| recognizedBy | distinct boundary clay layer in many sections ⓘ |
| relatedTo | Deccan Traps volcanism ⓘ |
| scientificDebate | relative roles of impact and volcanism in extinction ⓘ |
| separates | Upper Cretaceous strata from lower Paleogene strata ⓘ |
| stratigraphicRank | system/period boundary ⓘ |
| timeEquivalentOf |
Cretaceous–Paleogene boundary
self-linksurface differs
ⓘ
surface form:
Cretaceous–Paleogene extinction event
|
| usedIn |
biostratigraphy
ⓘ
chemostratigraphy ⓘ geochronology ⓘ magnetostratigraphy ⓘ |
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: Cretaceous–Paleogene boundary Description of subject: The Cretaceous–Paleogene boundary marks the geological transition 66 million years ago associated with a mass extinction event that wiped out non-avian dinosaurs and many other species, likely triggered by a large asteroid impact.
Referenced by (34)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Chicxulub impact event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Chicxulub impact event
this entity surface form:
K–Pg boundary
Cretaceous–Paleogene boundary
→
formerlyKnownAs
→
Cretaceous–Paleogene boundary
self-linksurface differs
ⓘ
this entity surface form:
Cretaceous–Tertiary boundary
this entity surface form:
K–T boundary
Cretaceous–Paleogene boundary
→
associatedWith
→
Cretaceous–Paleogene boundary
self-linksurface differs
ⓘ
this entity surface form:
Cretaceous–Paleogene extinction event
Cretaceous–Paleogene boundary
→
timeEquivalentOf
→
Cretaceous–Paleogene boundary
self-linksurface differs
ⓘ
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene mass extinction
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene boundary layer
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Gubbio K–Pg boundary section in Italy
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
International Ocean Discovery Program drilling project 364
→
linkedToEvent
→
Cretaceous–Paleogene boundary
ⓘ
this entity surface form:
Cretaceous–Paleogene mass extinction
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene mass extinction
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene extinction event
this entity surface form:
Cretaceous–Paleogene mass extinction