The Mesozoic Era is the second-to-last era of Earth's geological history, lasting from about 252 to 66 million years ago, comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of gymnosperms and of archosaurian reptiles, such as the dinosaurs; a hot greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic.
Plateosaurus (a prosauropod)
Sericipterus
Stegosaurus
Tylosaurus (a mosasaur) hunting Xiphactinus
The Triassic is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic.
Early Triassic sandstone (Buntsandstein) near Stadtroda, Germany
Middle Triassic Muschelkalk (shell-bearing limestone) near Dörzbach, Germany
Late Triassic Steigerwald Formation and overlying Hassberge Formation in Schönbuch, Germany
Sydney, Australia lies on Triassic shales and sandstones. Almost all of the exposed rocks around Sydney belong to the Triassic Sydney sandstone.
