| System (period) | Series (epoch) | Stage (age) | Lower boundary, Ma | |
|---|---|---|---|---|
| Jurassic | Lower | Hettangian | 201.4±0.2 | |
| Triassic | Upper (Late) | Rhaetian | ~208.5 | |
| Norian | ~227 | |||
| Carnian |  ~237
| |||
| Middle | Ladinian | ~242
| ||
| Anisian | 247.2 | |||
| Lower (Early) | Olenekian | 251.2 | ||
| Induan | 251.902±0.024
| |||
| Permian | Lopingian | Changhsingian | older | |
| Subdivisions and "golden spikes" according to IUGS as of September 2023[1] | ||||
Early Triassic sandstone from Germany
The Early Triassic is the first of three epochs of the Triassic period and the first epoch of the whole Mesozoic era of the geologic timescale. It spans the time between 251.902 Ma and 247.2 Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic series, which is a unit in chronostratigraphy.
The Early Triassic is the oldest epoch of the Mesozoic era. It is preceded by the Changhsingian age of the Lopingian epoch (late Permian, Paleozoic Era) and followed by the Anisian age of the Middle Triassic epoch.
Definition[]
The GSSP of the Lower Triassic also defines the base of the Induan stage, the Triassic system and the whole Mesozoic erathem. It was ratified in 2001. The lower boundary is fixed in the Meishan section in China and related to the first appearence of the conodont Hindeodus parvus.[2]
Subdivisions[]
The Early Triassic is divided into the Induan and Olenekian ages. Both of them correspond to the stages of the same names in stratigraphy. The Induan is subdivided into the Griesbachian and Dienerian subages and the Olenekian is subdivided into the Smithian and Spathian subages.
The Lower Triassic series is coeval with the Scythian stage, which is today not included in the official timescales but can be found in older literature. In Europe, most of the Lower Triassic is composed of Buntsandstein, a lithostratigraphic unit of continental red beds.
Early Triassic life[]
Early Triassic and Anisian marine predators: 1. Wantzosaurus, 2. Fadenia, 3. Saurichthys, 4. Rebellatrix, 5. Hovasaurus, 6. Birgeria, 7. Aphaneramma, 8. Bobasatrania, 9. Hybodontiformes, 10. Mylacanthus, 11. Tanystropheus, 12. Corosaurus, 13. Ticinepomis, 14. Mixosaurus, 15. Cymbospondylidae, 16. Neoselachii, 17. Omphalosaurus skeleton, 18. Placodus
References[]
- ↑ "Latest version of international chronostratigraphic chart". International Commission on Stratigraphy. https://stratigraphy.org/chart#latest-version.
- ↑ "GSSP Table - Mesozoic Era". https://timescalefoundation.org/gssp/index.php?parentid=35.