mass extinction

noun

plural mass extinctions

: an event in which many living species on Earth experience rapid extinction rates during a relatively short period of geologic time

Unless climate change is curbed, Earth's oceans could see a mass extinction of marine life unlike anything the planet has seen for millions of years …

—Doyle Rice

[Paleobiologist Anthony] Barnosky calculates that humans are now creating a mass extinction. … As many as 30% of all species may be lost over the next four decades, conservationists estimate.

—Gaia Vince

specifically : a rare event in which seventy-five percent or more of all living species on Earth die out within a relatively short period of geologic time and that is usually associated with catastrophic natural phenomena (such as volcanic eruptions or asteroid impacts)

… the most recent of five events in Earth's history that scientists consider mass extinctions, defined by paleontologists as events where more than 75 percent of species vanish within a geologically short period of time, typically less than two million years.

—Katarina Zimmer

About 252 million years ago, the vast majority of species on Earth were killed off in the "Great Dying," the worst mass extinction in our planet's history. Up to 96% of all marine species and 70% of land animals were killed off during this event …

—Peter Kotecki

We are still far from meeting the requirements that paleontologists set for a "mass extinction event" (loss of 75 percent of species globally). However, in geologic time, we are moving towards that reality.

—Gabe Allen

The Triassic mass extinction event took place 200 million years ago, eliminating about 80% of Earth's species, including many types of dinosaurs.

—Tammana Begum

Examples of mass extinction in a Sentence

Recent Examples on the Web

Late last year, a new study reignited the age-old argument over just what caused the mass extinction of the ancient beasts 66 million years ago, positing that volcanic eruptions – not just the infamous meteor – played a role in wiping out the dinosaurs. —Eric Lagatta, USA TODAY, 4 Jan. 2024

Of Time and Turtles: Mending the World, Shell by Shattered Shell by Sy Montgomery Scuttling Earth for at least 220 million years, turtles have survived more than one mass extinction, including the one that offed dinosaurs. —Bridget Alex, Smithsonian Magazine, 7 Dec. 2023

Genomic analysis indicated that psychedelic mushrooms emerged around the time of the Mesozoic–Cenozoic mass extinction. —Rafil Kroll-Zaidi, Harper's Magazine, 27 Mar. 2024

Yet many of the planet’s most significant happenings are called events, including mass extinctions, rapid expansions of biodiversity and the filling of Earth’s skies with oxygen 2.1 to 2.4 billion years ago. —Raymond Zhong, New York Times, 5 Mar. 2024

Their proper care and study seems of particular urgency to scientists now, because after all, dinosaurs and 21st-century humanity have something in common: living in an epoch of mass extinctions and climate change. —Dennis Harvey, Variety, 18 Mar. 2024

Instead, titanosaurs were among the witnesses to – and victims of – the most recent mass extinction on Earth. —Kristi Curry Rogers, The Conversation, 7 Mar. 2024

The Ordovician period came to a chaotic end with a major mass extinction event that rocked Earth, eliminating about 85 percent of all species. —Jack Knudson, Discover Magazine, 9 Feb. 2024

Having lived on Earth for at least 600 million years, water bears persisted through all five mass extinction events. —Christian Thorsberg, Smithsonian Magazine, 18 Jan. 2024

Word History

First Known Use

1943, in the meaning defined above