The history of life has been punctuated by several mass extinctions. For example, the impact of a meteorite may have wiped out most of the dinosaurs and many forms of marine life at the end of the Cretaceous period (see Concept 25.4). Fossils indicate that plants were less severely affected by this mass extinction. What adaptations may have enabled plants to withstand this disaster better than animals?

Mass extinction is an event that rapidly destroys the majority of the biodiversity of the Earth. It eliminated almost 75% of the species. It occurs when species are depleted faster than they are replaced.

Cretaceous-Tertiary Extinction occurred 65 million years ago at the end of the Cretaceous period and at the beginning of the Tertiary period. This extinction wiped out all the dinosaurs from the Earth.

The extinction is supposed to be caused by an asteroid impact that led to volcanic eruptions changing the climate of the Earth. As a result, dinosaurs could not survive in the changed atmosphere and became extinct.

Although the mass extinction destroyed 70% of species on Earth, plants and trees survived the severe destruction caused by the asteroid. Through their seeds, these life forms could withstand the adverse conditions caused by the impact event.

These seeds could survive the nuclear winter because they can remain dormant for lengthy periods. Plant development was impossible after the great extinction, but plants remained dormant as seeds in a latent state until conditions improved.

This explains why plant species did not suffer as much as animal species during the extinction.