The Triassic period is the first period of the Mesozoic Era, lasting from about 252 to 201 million years ago. It followed the largest mass extinction in Earth's history, the Permian-Triassic extinction, which wiped out many species. The climate during the Triassic was generally warm and dry, leading to the development of diverse ecosystems. During the Triassic, the first dinosaurs and mammals appeared, marking significant evolutionary advancements. The period is divided into three epochs: Early Triassic, Middle Triassic, and Late Triassic. The Pangaea supercontinent began to break apart, influencing the distribution of species and habitats.