Proterozoic Eon
E6725
The Proterozoic Eon is a major division of Precambrian time, spanning from about 2.5 billion to 541 million years ago, marked by the buildup of atmospheric oxygen, the emergence of complex single-celled and early multicellular life, and the assembly of large continental landmasses.
All labels observed (5)
| Label | Occurrences |
|---|---|
| Proterozoic Eon canonical | 25 |
| Proterozoic | 6 |
| Great Oxidation Event | 1 |
| Proterozoic Eonothem | 1 |
| Proterozoic erathem | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T60777 — 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: Proterozoic Eon Context triple: [Canadian Shield, geologicalEraFormation, Proterozoic Eon]
-
A.
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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B.
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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C.
Old Red Sandstone
Old Red Sandstone is a thick sequence of Devonian-age sedimentary rocks, notable for its red coloration and widespread occurrence across parts of Scotland and other regions of the North Atlantic.
-
D.
Iapetus
Iapetus is a Titan from Greek mythology, often associated with mortality and craftsmanship and known as the father of Prometheus, Epimetheus, Atlas, and Menoetius.
-
E.
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.
- 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: Proterozoic Eon Target entity description: The Proterozoic Eon is a major division of Precambrian time, spanning from about 2.5 billion to 541 million years ago, marked by the buildup of atmospheric oxygen, the emergence of complex single-celled and early multicellular life, and the assembly of large continental landmasses.
-
A.
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.
-
B.
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.
-
C.
Old Red Sandstone
Old Red Sandstone is a thick sequence of Devonian-age sedimentary rocks, notable for its red coloration and widespread occurrence across parts of Scotland and other regions of the North Atlantic.
-
D.
Iapetus
Iapetus is a Titan from Greek mythology, often associated with mortality and craftsmanship and known as the father of Prometheus, Epimetheus, Atlas, and Menoetius.
-
E.
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.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
division of Precambrian time
ⓘ
geologic eon ⓘ |
| associatedWith |
decline of anaerobic microbial dominance
ⓘ
expansion of aerobic metabolisms ⓘ first known eukaryotic microfossils ⓘ first known multicellular algae ⓘ first macroscopic animal fossils in Ediacaran ⓘ oxygenation of surface oceans ⓘ rise of atmospheric oxygen to near-modern levels ⓘ |
| characterizedBy |
Ediacaran biota
ⓘ
Proterozoic Eon self-linksurface differs ⓘ
surface form:
Great Oxidation Event
Snowball Earth events ⓘ appearance of earliest animals ⓘ assembly of large continental landmasses ⓘ buildup of atmospheric oxygen ⓘ decline of banded iron formations after oxygen rise ⓘ development of plate tectonics similar to modern style ⓘ emergence of complex single-celled life ⓘ emergence of early multicellular life ⓘ evolution of algae ⓘ evolution of eukaryotes ⓘ first widespread glaciations ⓘ increased biological complexity ⓘ major changes in ocean chemistry ⓘ stabilization of continental cratons ⓘ supercontinent cycles ⓘ widespread banded iron formations in early Proterozoic ⓘ |
| chronostratigraphicUnit |
Proterozoic Eon
self-linksurface differs
ⓘ
surface form:
Proterozoic Eonothem
|
| contains |
Mesoproterozoic Era from about 1.6 to 1.0 billion years ago
ⓘ
Neoproterozoic Era from about 1.0 billion to 541 million years ago ⓘ Paleoproterozoic Era from about 2.5 to 1.6 billion years ago ⓘ |
| duration | approximately 2 billion years ⓘ |
| endDefinedBy | base of Cambrian Period ⓘ |
| endTime | about 541 million years ago ⓘ |
| followedBy | Phanerozoic Eon ⓘ |
| followedByEvent | Cambrian explosion ⓘ |
| follows | Archean Eon ⓘ |
| geochronologicRank | eon ⓘ |
| includes |
supercontinent Columbia (Nuna)
ⓘ
supercontinent Pannotia ⓘ supercontinent Rodinia ⓘ |
| locationInTimeScale | between Archean and Phanerozoic on geologic timescale ⓘ |
| partOf | Precambrian Supereon ⓘ |
| precededByEvent | Archean crust formation ⓘ |
| startTime | about 2.5 billion years ago ⓘ |
| subdivision |
Mesoproterozoic Era
ⓘ
Neoproterozoic Era ⓘ Paleoproterozoic Era ⓘ |
| usedIn |
International Commission on Stratigraphy
ⓘ
surface form:
International Commission on Stratigraphy timescale
|
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: Proterozoic Eon Description of subject: The Proterozoic Eon is a major division of Precambrian time, spanning from about 2.5 billion to 541 million years ago, marked by the buildup of atmospheric oxygen, the emergence of complex single-celled and early multicellular life, and the assembly of large continental landmasses.
Referenced by (34)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Great Oxidation Event
this entity surface form:
Proterozoic Eonothem
subject surface form:
Rodinia
subject surface form:
Rodinia
subject surface form:
Pannotia
this entity surface form:
Proterozoic
this entity surface form:
Proterozoic
this entity surface form:
Proterozoic erathem
this entity surface form:
Proterozoic
this entity surface form:
Proterozoic
this entity surface form:
Proterozoic
this entity surface form:
Proterozoic