The Permian-Triassic Extinction appears on the 2018 Lp, Gemini.
The Permian extinction was characterized by the elimination of over 95 percent of marine and 70 percent of terrestrial species. In addition, over half of all taxonomic families present at the time disappeared. Likely caused by the Warming of the Earth's climate and associated changes to the oceans. The Permian extinction event ranks first in severity of the five major extinction episodes that span geologic time. Therapsids are the stock that gave rise to mammals and are the most closet ancient relative of mammals. The cynodont therapsids survived the greatest mass extinction of all time, 252 million years ago, and thrived in the aftermath.