Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Extinct organisms are species that no longer exist anywhere on Earth.
Related terms
Endangered Species: These are species that aren't extinct yet but their populations are so low they're at risk for extinction.
Biodiversity Loss: This refers to the decrease in variety and variability among living organisms including diversity within species (genetic diversity), between species (species diversity), and between ecosystems (ecosystem diversity).
Mass Extinction Event: An event during which many species become extinct over a relatively short period due to catastrophic global events or rapid environmental change.