出典:Wikipedia
出典:『Wikipedia』 (2011/05/14 10:52 UTC 版)
The Early Triassic is the first of three epochs of the Triassic period of the geologic timescale. It spans the time between 251 ± 0.4 Ma and 245 ± 1.5 Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic, which is a unit in chronostratigraphy. The Early Triassic is the oldest epoch of the Mesozoic era and is divided into the Induan and Olenekian ages.