mass extinction event

noun

One of five historical events in which the Earth experienced a loss of ∼75% of all species over a geological interval of less than 3 million years, the most recent being the Cretaceous–Paleogene extinction event 66 million years ago.

Meanings

nounmass extinction event (plural mass extinction events)

plural mass extinction events

  1. evolutionary theorygeographyOne of five historical events in which the Earth experienced a loss of ∼75% of all species over a geological interval of less than 3 million years, the most recent being the Cretaceous–Paleogene extinction event 66 million years ago.

    “As a utopia, it’s a very low bar,” Robinson said. “I mean, if we avoid the mass extinction event, we avoid everything dying, great, that’s utopia, given where we are now.”

    2022 May 11, Alexandra Alter, quoting Kim Stanley Robinson, “A Sci-Fi Writer Returns to Earth: ‘The Real Story Is the One Facing Us’”, in The New York Times, →ISSN
    1 more example

    Joab is a two-mooned habitable planet that is most well known for its mass extinction event. Thousands of years ago, Joab was home to a primate-like spacefaring civilization as well as abundant flora and fauna. However, this can only be deduced from time capsules put into the ground well outside habitation centers -- all cities and detectable dwellings were targeted in a massive orbital bombardment that turned them into vapor. The resulting dust shroud killed all photosynthetic life and all fauna dependent on it.

    2010, BioWare, Mass Effect 2 (Science Fiction), Redwood City: Electronic Arts, →OCLC, PC, scene: Joab

Synonyms & antonyms

Cite this entry
APA

mass extinction event. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/mass%20extinction%20event

MLA

“mass extinction event.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/mass%20extinction%20event. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “mass extinction event,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/mass%20extinction%20event.

Source: mass extinction event on Wiktionary, CC BY-SA 4.0.