Triassic Period

The Triassic Period is the first period of the Mesozoic Era; it extended from 252 to 199 million years ago with a duration of 52.4 million years. The Triassic System includes the rocks that formed during the Triassic Period. It was named after a site in southern Germany, where the lithological characteristics are distinctively tripartite. During the Triassic Period, the land area continued to expand, and the sea surface decreased. Terrestrial facies strata are well developed with lush terrestrial plants, and this period was another important interval of coal formation. Invertebrates such as ammonites and belemnites developed rapidly. Vertebrates began to flourish, whereas primitive dinosaur species and mammal-like species developed rapidly in the Late Triassic Epoch. The Triassic System is widely distributed in China with rich biota. Due to the folding and crustal uplift in the late Palaeozoic Era, China’s Triassic Period was roughly bounded by the Kunlun-Qinling-Dabieshan line,...