Most animals and plants that ever lived died out long before the present. The fossil record reveals that there are several periods of time in the earth's past when the extinction rate was very high (e.g., at the Cretaceous/Tertiary boundary, and the Permian/Triassic boundary) - causing mass extinctions of a large percentage of the species.
This category contains sites dealing with the subjects of extinction and mass extinctions in the fossil record.
This category is for websites dealing with the scientific study of the end-Mesozoic mass extinction.
The extinction at the end of the Paleozoic was the largest recorded in the fossil record. Theories abound as to why this extinction occurred. The world was irrevocably changed after this event, which marked the end of many characteristically Paleozoic lineages. This category is for sites specifically dealing with this extinction.
Websites about extinction phenomena in the Holocene Epoch (approximately the last 10,000 years), particularly past, ongoing, and future extinctions due to the actions of humans.