What are the major mass extinction events of the Phanerozoic eon?

Mass extinction events are rapid and widespread decreases in Earth's biodiversity, identified by a sharp fall in the diversity and abundance of multicellular organisms. Estimates of major mass extinctions in the last 540 million years range from five to over twenty, depending on how major events are defined. The best-known group of these is the traditional "Big Five" mass extinctions of the Phanerozoic eon.

What we know

• Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty due to differing definitions and data choices. [2]
• The Permian-Triassic extinction event is Earth's most severe known extinction event, eliminating 81 percent of marine species and 70 percent of terrestrial vertebrate species. [4]
• The Late Ordovician mass extinction eliminated 49 to 60 percent of marine genera and nearly 85 percent of marine species in two main pulses. [5]
• The Capitanian mass extinction event is considered the third-largest of the Phanerozoic in terms of genera and species lost, though its global nature has been questioned. [3] · medium confidence

Still open

• There is disagreement among scientists on the exact number of major mass extinction events, ranging from five to over twenty.
• Some paleontologists question whether the Capitanian mass extinction was truly global, as some analyses suggest it only affected low-latitude taxa in the Northern Hemisphere.

Where to go next

• what caused itWhat caused the Permian-Triassic extinction?
• what followedHow did marine life recover after the Late Ordovician extinction?
• how it workedHow do scientists identify past extinction events in the fossil record?
• how we knowWhat evidence supports the Big Five mass extinctions?
• whenWhen did the Capitanian mass extinction occur?
• an unexpected connectionCan volcanic eruptions trigger mass extinctions?Massive flood basalt eruptions like the Siberian Traps released massive amounts of carbon dioxide and sulfur dioxide, drastically altering global climate and chemistry.

Sources

• [1]extinction event (Wikidata Q55814) · CC0 1.0
• [2]Extinction event · CC BY-SA 4.0
• [3]Capitanian mass extinction event · CC BY-SA 4.0
• [4]Permian–Triassic extinction event · CC BY-SA 4.0
• [5]Late Ordovician mass extinction · CC BY-SA 4.0

Your path

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2. /Why do people choose to take boudoir photographs?
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4. /What are the major mass extinction events of the Phanerozoic eon?