Final answer:
The end-Permian extinction was the largest mass extinction event, with around 96% of marine species and 70% of terrestrial species lost, likely due to extended volcanic activity causing a global-warming event.
Step-by-step explanation:
The largest mass extinction in Earth's history was the end-Permian extinction. This catastrophic event resulted in the loss of an estimated 96 percent of all marine species and 70 percent of terrestrial species, effectively altering Earth's biodiversity and the course of evolution. Among the marine species that became extinct were the trilobites. The leading hypothesis for the cause of this mass extinction involves extended volcanic activity that contributed to a runaway global-warming event, causing oceans to become anoxic and suffocating marine life. Recovery from the Permian extinction took millions of years for terrestrial tetrapod diversity.