Summary
Five major events, including the end-Permian and end-Cretaceous, that wiped out large fractions of species.
In depth
The 'Big Five': end-Ordovician (about 445 mya), late Devonian (372), end-Permian (252, about 90 percent of marine species lost), end-Triassic (201) and end-Cretaceous (66, non-avian dinosaurs). Causes include volcanism, climate change and, for the last, an asteroid impact at Chicxulub.
Recovery took millions of years and reshaped life.
Causes include volcanism (Siberian Traps at the end-Permian, causing warming, ocean acidification and anoxia), asteroid impact (the 10 km Chicxulub impactor at the end-Cretaceous, with iridium layer found by the Alvarezes) and climate change. Recoveries took millions of years, and survivors often differ from the dominant groups before.
Survivors are not always the best adapted; luck and traits such as small body size, wide ranges and burrowing helped. After the end-Permian, life was dominated by new groups, and the end-Cretaceous allowed mammals to expand. Many scientists suggest we may be entering a sixth extinction driven by humans.
Example: trilobites, abundant for 270 million years, were wiped out at the end-Permian.
Frequently asked questions
What is Mass Extinctions?
Five major events, including the end-Permian and end-Cretaceous, that wiped out large fractions of species.
Which area of biology covers Mass Extinctions, and how advanced is it?
Mass Extinctions is one of the 53 topics in Evolution. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Extinction, Macroevolution, Adaptive Radiation.
Can you give an example of Mass Extinctions?
Mammals diversified after the dinosaurs disappeared.
What should I learn before Mass Extinctions?
Work through the Beginner topics in Evolution first, such as Evolution, Natural Selection, Charles Darwin, then return to Mass Extinctions. Intermediate topics assume the Beginner vocabulary.
What topics are related to Mass Extinctions?
The closest topics to Mass Extinctions are Extinction, Macroevolution, Adaptive Radiation, Cambrian Explosion. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Mass Extinctions?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Mass Extinctions. To practise the whole of Evolution, use the Evolution quiz.
How is Mass Extinctions different from Extinction?
Mass Extinctions: Five major events, including the end-Permian and end-Cretaceous, that wiped out large fractions of species. Extinction: The permanent disappearance of a species, occurring naturally and at accelerated rates today. Read both side by side and note what each one explains.
How should I study Mass Extinctions step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Extinction and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.