Triassic Triassic The Triassic () is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.9 million years ago (Mya), to the beginning of the Jurassic Period Mya. The Triassic is the first period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it would take well into the middle of this period for life to recover its former diversity. Therapsids and archosaurs were the chief terrestrial
Geography of Switzerland term covers entire geological movements contributing to the of the Alps’ formation. A crystalline basement formed at the beginning of the Paleozoic era, between 540 and 360 millions years ago. Later, between 205 and 96 million years ago, the alpine ocean or Tethys Ocean formed between Eurasia and Africa. The ocean reached its maximum width at the end of Jurassic period, 135 million years ago. The collision between the Eurasian and African plates made it progressively disappear. This plate collision (still in progress) began 100 million years ago. The Alps resulted from this geological movement, the two plates creating folding