Similar to C-O境界

86400 (number)

144,000

800,000

2,147,483,647

Extinction event

Cenomanian-Turonian boundary event

Late Devonian mass extinction

Late Ordovician mass extinction

Anoxic event

Holocene extinction

Cretaceous–Paleogene boundary

Snowball Earth

Great Oxidation Event

Late Pleistocene extinctions

Chicxulub crater

Middle Maastrichtian Event

Triassic–Jurassic extinction event

Nemesis (hypothetical star)

Cretaceous–Paleogene extinction event