Major Phanerozoic extinction intervals
The end-Ordovician, Late Devonian, end-Permian, end-Triassic and end-Cretaceous intervals mark especially prominent losses in the Phanerozoic fossil record.
Key knowledge
The end-Ordovician, Late Devonian, end-Permian, end-Triassic and end-Cretaceous intervals mark especially prominent losses in the Phanerozoic fossil record. They differ in duration, affected groups and environmental evidence; some contain multiple pulses. The end-Cretaceous loss includes non-avian dinosaurs while birds survived. This conventional group is not a claim that only five extinction crises occurred.
Conditions and scope
- Comparisons depend on taxonomic level, sampling, preservation, age resolution and the marine or terrestrial record being examined.
- An extinction horizon and evidence for its cause are distinct claims. Exact loss percentages and unique mechanisms are not inferred merely from a missing fossil in one local section.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Read the actual introductory list, marine-taxonomic evidence, Late Devonian uncertainty and end-Cretaceous avian qualification. Retained no contested exact global extinction percentage or blanket single-cause assertion.
2026-10-10 · Independent AI editorial review: All73 exact supplement compact statements, conditions, displayed equations and247 origin semantic links read; all109 combined original36+supplement73 author-source rows, exact locators, hypotheses, exclusions and disclosed derivations assessed. Original36 exact scientific content is independently approved in the linked receipt. All18 inherited Earth compact references and shared Math/Physics/Measurement methods were considered in the full practical Earth inventory. Targeted actual primary sections listed below; not every source body/proof or every possible university elective independently reread. AI editorial reference review, not human certification, full-degree proficiency, new experimental validation or a claim of whole combined Earth-and-Cosmos approval. Receipt: earth-completion-independent-content-inventory-review.1.
Entry details
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