From 190 million to 230 million years ago; dinosaurs, marine reptiles; volcanic activity; Also called: Triassic period.
Period of geological time 245–208 million years ago, the first period of the Mesozoic era. The continents were fused together to form the world continent Pangaea. Triassic sediments contain remains of early dinosaurs and other reptiles now extinct. By late Triassic times, the first mammals had evolved.
From 135 million to 190 million years ago; dinosaurs; conifers; Also called: Jurassic period.
Period of geological time 208–146 million years ago; the middle period of the Mesozoic era. Climates worldwide were equable, creating forests of conifers and ferns; dinosaurs were abundant, birds evolved, and limestones and iron ores were deposited.
The name comes from the Jura mountains in France and Switzerland, where the rocks formed during this period were first studied.
In North America, the Nevadan orogeny marked the beginning of the Sierra Nevadas and other mountains.
Era of geological time 245–65 million years ago, consisting of the Triassic, Jurassic, and Cretaceous periods. At the beginning of the era, the continents were joined together as Pangaea; dinosaurs and other giant reptiles dominated the sea and air; and ferns, horsetails, and cycads thrived in a warm climate worldwide. By the end of the Mesozoic era, the continents had begun to assume their present positions, flowering plants were dominant, and many of the large reptiles and marine fauna were becoming extinct.
From 63 million to 230 million years ago; Also called: Mesozoic era, Age of Reptiles.