Early Triassic

The Early Triassic (also known as Lower Triassic, Buntsandstein, or Scythian) is the first of three epochs of the Triassic period. It spans the time between 251 ± 0.4 Ma and 245 ± 1.5 Ma (million years ago). The Permian-Triassic extinction event spawned the Triassic period. It also marked the beginning of the Mesozoic era and is divided into the Induan and Olenekian faunal stages. The massive extinctions that ended the Permian period and Paleozoic era caused extreme hardships for the surviving species. Many types of corals, brachiopods, molluscs, echinoderms, and other invertebrates had completely disappeared. The most common Early Triassic hard-shelled marine invertebrates were bivalves, gastropods, ammonoids, echinoids, and a few articulate brachiopods. The most common land animal was a small herbivorous synapsid Lystrosaurus. Early Triassic faunas lacked biodiversity and were relatively homogenous throughout the epoch due to the effects of the extinction. The climate during the Early Triassic epoch (especially in the interior of the supercontient Pangaea) was generally arid and dry and deserts were widespread however the poles possessed a Temperate climate. The relatively hot climate of the Early Triassic may have been caused by widespread volcanic eruptions which accelerated the rate of global warming and possibly caused the Permian Triassic extinction event.

See also

* Geologic time scale

References

* [http://www.stratigraphy.org/geowhen/stages/Early_Triassic.html GeoWhen Database - Early Triassic]
* [http://www.palaeos.com/Mesozoic/Triassic/EarlyTrias.htm Palaeos]
* [http://www.scotese.com/etriascl.htm scotese]