Although the Cretaceous-Tertiary (or K-T) extinction event is the most well-known because it wiped out
the dinosaurs, a series of other mass extinction events has occurred throughout the history of the Earth,
some even more devastating than K-T. Mass extinctions are periods in Earth's history when abnormally
large numbers of species die out simultaneously or within a limited time frame. The most severe occurred
at the end of the Permian period when 96% of all species perished. This along with K-T are two of the
Big Five mass extinctions, each of which wiped out at least half of all species. Many smaller scale
mass extinctions have occurred, indeed the disappearance of many animals and plants at the hands of
man in prehistoric, historic and modern times will eventually show up in the fossil record as mass
extinctions. Discover more about Earth's major extinction events below.
Ordovician-Silurian mass extinction
The third largest extinction in Earth's history, the Ordovician-Silurian mass extinction had two peak dying times separated by hundreds of thousands of years. During the Ordovician, most life was in the sea, so it was sea creatures such as trilobites, brachiopods and graptolites that were drastically reduced in number.
Late Devonian mass extinction
Three quarters of all species on Earth died out in the Late Devonian mass extinction, though it may have been a series of extinctions over several million years, rather than a single event. Life in the shallow seas were the worst affected, and reefs took a hammering, not returning to their former glory until new types of coral evolved over 100 million years later.
Permian mass extinction
The Permian mass extinction has been nicknamed The Great Dying, since a staggering 96% of species died out. All life on Earth today is descended from the 4% of species that survived.
Triassic-Jurassic mass extinction
During the final 18 million years of the Triassic period, there were two or three phases of extinction whose combined effects created the Triassic-Jurassic mass extinction event. Climate change, flood basalt eruptions and an asteroid impact have all been blamed for this loss of life.
Cretaceous-Tertiary mass extinction
The Cretaceous-Tertiary mass extinction - also known as the K/T extinction - is famed for the death of the dinosaurs. However, many other organisms perished at the end of the Cretaceous including the ammonites, many flowering plants and the last of the pterosaurs.