The Triassic is a period of time which extends from 251 to 199.6 Mya (million years ago). The name Triassic was coined by German geologist Friedrich Von Alberti in 1834, and relates to the three distinct rock layers that formed during the era. These rock layers can be seen throughout Germany and northwestern Europe and are formed of a layer of red beds, capped by a layer of chalk, followed by black shales.
The Triassic follows a period of time known as the Permian, and began in the wake of the Permian-Triassic extinction event; an event which left the Earth’s biosphere impoverished. Terrestrial life did not fully recover and diversify until midway through the Triassic era. The shelled, marine-dwelling, ammonites recovered, expanding from a single line which survived the Permian extinction. The fish fauna for the period remained very uniform, highlighting the fact that very few fish families survived through to the Triassic. Despite this, there were a large number of marine reptiles present throughout the Triassic. These included pachypleurosaurs, nothosaurus, placodonts, the first plesiosaurs and the highly successful ichthyosaurs.
On land, the early Triassic period was dominated by basal amphibians and a handful of therapsids (the ancestors of mammals), which had managed to survive the extinction event. However as the Triassic period progressed the therapsids were slowly displaced by archosaur reptiles (the ancestors of dinosaurs). The increase in archosaur numbers likely forced the surviving therapsids and their mammalian succesors to live as small, mainly nocturnal insectivores. The archosaurs on the other hand, evolved at a rapid pace, with different clades of archosaur evolving into different things. By the mid-Triassic the first pterosaurs and dinosaurs were present; but shared land space with a number of other reptile groups, including the aetosaurs, the rhynchosaurs, the first turtles, and the first crocodilians (the sphenosuchians).
Geography & Climate:
During the Triassic, almost all the Earth’s land mass was concentrated into a single supercontinent, known as Pangea. The mid-Traissic saw Pangea begin to gradually rift into two separate landmassed, Laurasia to the north and Gondwana to the south. The global climate during the Triassic was mostly hot and dry, with deserts spanning much of Pangaea’s interior. However, the climate shifted and became more humid as Pangaea began to drift apart. There is no evidence of glaciation at or near either pole; in fact, the polar regions were apparently moist and temperate, a climate suitable for reptile-like creatures.
This following few weeks will be dedicated to all things Triassic! To begin with we will look at all the non-dinosaur animals which lived during the Triassic period, and eventually build this up into some detailed Triassic dinosaur fact-files. So if there is a Triassic dinosaur you want a fact-file about, please, please, please let me know!
Unfortunately I am going to be away for a few days and will not have access to an internet connection, meaning Dino-Files is having to be put on hold until Friday.
In the meantime, check out some of the latest fact files below:
And check back tomorrow for a post regarding dino-file requests!