Pangaea's large size limited the moderating effect of the global ocean; its continental climate was highly seasonal, with very hot summers and cold winters.The Triassic may have mostly been a dry period, but evidence exists that it was punctuated by several episodes of increased rainfall in tropical and subtropical latitudes of the Tethys Sea and its surrounding land.The vast supercontinent of Pangaea existed until the mid-Triassic, after which it began to gradually rift into two separate landmasses, Laurasia to the north and Gondwana to the south.
Diverse communities with complex food-web structures took 30 million years to reestablish.
Temnospondyl amphibians were among those groups that survived the Permian-Triassic extinction; some lineages (e.g.
Because a super-continental mass has less shoreline compared to one broken up, Triassic marine deposits are globally relatively rare, despite their prominence in Western Europe, where the Triassic was first studied.
In North America, for example, marine deposits are limited to a few exposures in the west.
A specialized subgroup of archosaurs, called dinosaurs, first appeared in the Late Triassic but did not become dominant until the succeeding Jurassic Period.
The first true mammals, themselves a specialized subgroup of Therapsids, also evolved during this period, as well as the first flying vertebrates, the pterosaurs, who like the dinosaurs were a specialized subgroup of archosaurs.
Subequatorial saurichthyids have also been described in Early Triassic strata.
The Permian-Triassic extinction devastated terrestrial life. Biodiversity rebounded as the surviving species repopulated empty terrain, but these were short lived.
Sediments and fossils suggestive of a more humid climate are known from the Anisian to Ladinian of the Tethysian domain, and from the Carnian and Rhaetian of a larger area that includes also the Boreal domain (e.g., Svalbard Islands), the North American continent, the South China block and Argentina.
The best studied of such episodes of humid climate, and probably the most intense and widespread, was the Carnian Pluvial Event.
All the deep-ocean sediments laid down during the Triassic have disappeared through subduction of oceanic plates; thus, very little is known of the Triassic open ocean.