Triassic Period

The great extinction that wiped out all the dinosaurs, large and small, in all parts of the world, and at the same time brought to an end various lines of reptilian evolution, was one of the outstanding events in the history of life and in the history of the earth.... It was an event that has defied all attempts at a satisfactory explanation.
~ Edwin H. Colbert

Indeed, despite zillions of theories have sprung up as attempts at explaining the sudden extinction of these prodigious saurians from the face of our planet, there have hardly been any unanimity of preference with regards to agreeing upon any one particular theory. The Triassic Period is one such period of the evolution of Earth and its biosphere which witnessed the emergence of the widest variety of life forms and, conversely, the biggest wave of extinction among all geologic periods. Let's get a load on some interesting Triassic Period facts.

Triassic Period Timeline and Duration
Let's begin with when it all started. The Triassic Period was preceded by the Permian Period and succeeded by the Jurassic Period. It was the first geologic period of the Mesozoic Era and it is divided into three epochs (tens of millions of years). Each of these epochs are further subdivided into various stages spanning over a particular period of time. Therefore, we can say that the Triassic Period lasted between approximately 250 million years ago till 200 million years ago and its break up into various epochs and stages can be chronologically depicted as follows:-

Triassic Period Break-Up
Epoch	Stages	Time Span (in Mya)
Late Triassic Period	Rhaetian Stage	203.6 ± 1.5 till 199.6 ± 0.6
	Norian Stage	216.5 ± 2.0 till 203.6 ± 1.5
	Carnian Stage	228.0 ± 2.0 till 216.5 ± 2.0
Middle Triassic Period	Ladinian Stage	237.0 ± 2.0 till 228.0 ± 2.0
	Anisian Stage	245.0 ± 1.5 till 237.0 ± 2.0
Early Triassic Period	Olenekian Stage	249.7 ± 0.7 till 245.0 ± 1.5
	Induan Stage	251.0 ± 0.4 till 249.7 ± 0.7

Climate
The geological composition of Earth in the Triassic Period chiefly constituted of red hued sedimentary rocks such as sandstone and shale and evaporites. The reason behind such geological formations was the Triassic Period climate which tended towards temperatures and dry atmosphere. The polar regions had a temperate and moist climate with no trace of glaciation. It is in the then rainforest like climate of the poles that most reptiles and related creatures thrived. Cross equatorial monsoons occurred seasonally across the single, unified continental landmass of the Triassic Period.

Flora and Fauna
Plant life forms belonging to the divisions lycophyta, cycadophyta and ginkophyta constituted of the Triassic Period flora. Triassic Period animals a wide variety of amphibians, crustaceans, fish, insects, mammals, mollusks, reptiles and synapsids. Agrosaurus, Plateosaurus, Cryptoraptor, Gojirasaurus and Eoraptor are some of the few among a wide variety of Triassic Period dinosaurs.

What Happened in the Triassic Period?
The Triassic Period was an evolutionary extravaganza and full of transitions - both progressive as well as regressive. While on one hand a large number of species walked the Earth and swam the seas, the mass extinction during the late Triassic period wiped out much of it , making this period the cradle of oblivion for the most number of extinct animals. The oceans and marine life forms faced this heat the most. There is considerable debate surrounding the exact reason behind such a large-scale extinction. Around the same time when these extinctions occurred, a huge volcanic eruption is believed to have taken place and many believe this to be a reason. This eruption caused many parts to break off from the unified continental landmass and drift away as separate landmasses.

This coincided with a global cooling of the Earth and a significant bolide impact caused by a meteorite entering the earth's atmosphere. It is believed that these occurrences were collectively responsible for the sudden extinction of many prehistoric life forms from Earth. Those creatures who were ill-suited to these sudden environmental developments and failed to adapt to these changes died out.

That was a brief account of the events and going-ons of this prehistoric period. It's all a part and parcel of the evolutionary machinery and this thought has been very aptly put to the pen by Stephen J. Gould when he said:

If one small and odd lineage of fish had not evolved fins capable of bearing weight on land (though evolved for different reasons in lakes and seas,) terrestrial vertebrates would never have arisen. If a large extraterrestrial object-the ultimate random bolt from the blue-had not triggered the extinction of dinosaurs 65 million years ago, mammals would still be small creatures, confined to the nooks and crannies of a dinosaur's world, and incapable of evolving the larger size that brains big enough for self-consciousness require. If a small and tenuous population of protohumans had not survived a hundred slings and arrows of outrageous fortune (and potential extinction) on the savannas of Africa, then Homo sapiens would never have emerged to spread throughout the globe. We are glorious accidents of an unpredictable process with no drive to complexity, not the expected results of evolutionary principles that yearn to produce a creature capable of understanding the mode of its own necessary construction.