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
South German Jurassic South German Jurassic The term South German Jurassic () in earth history is used to refer to a lithostratigraphic rock unit at the hierarchical level of a super group. The rocks of the South German Jurassic were mainly deposited during the Jurassic period about 199 to 146 million years ago. The boundaries of the South German Jurassic and those of the chronostratigraphic or international Jurassic are not, however, exactly coincident. The depositions began rather later than the date of the international Triassic/Jurassic boundary and end as a result of erosion of the uppermost strata at various times during the Upper