The Permian-Triassic Extinction is a mass extinction that occurred between the Permian and Triassic geological periods approximately 250 million years ago; it is the deadliest of all the extinctions that have occurred on Earth. Furthermore, during the Permian-Triassic extinction the continents of today existed as a single supercontinent known as Pangea. This was the first time in history that the continental or land mass exceeded that of the ocean. This was even before the dinosaurs of the Triassic period roamed the Earth, during this period animals such as therapsids and synapsids such as pelycosaurs, insects and amphibians also occupied the Earth. The fauna that existed during the Permian period includes gymnosperms or seed-producing plants such as conifers. Other animals that existed during this period include marine life such as brachiopods (clams), bryozoans (coral-like skeletons), bony fish, and sharks, as well as crinoids (sea urchin-like creatures). According to National Geographic, approximately 90% of all animals and wildlife in this period perished, marine life being the hardest hit...