The Triassic period occurred 248 million years ago, and was home to an Earth that was unimaginably different than the one that exists today. During this period, which lasted until about 208 million years ago (40 million years), the world was changing drastically. The Triassic began right after the end of the Permian period, which brought about a mass extinction, losing about 90 percent of the world’s life.
Life rebounded. The Triassic was a division of the Mesozoic era, which is often referred to as the “Age of Reptiles,” but reptiles were only just evolving, so this term better applies to the later Jurassic and Cretaceous periods of the Mesozoic era, where dinosaurs really flourished.
Triassic Living Conditions
The end of the Permian period ushered in the end of the Paleozoic era, marking the beginnings of the Mesozoic era and the opening act, the Triassic period. During this time, the continents had not yet separated, and Pangea dominated the ocean with its massive, singular presence. It is believed to have been C-shaped, surrounded by the Panthalassia Ocean and the Tethys Sea (which filled up the inside section of the C).
Since the modern versions of continents hadn’t really even begun to form yet at the outset of the Triassic period, the climate was warm and dry. Only the coastal areas would have been cooler and more humid, and thanks to the shape of Pangea and its location on the equator, the central, inland areas would likely have been like deserts.
About halfway through the Triassic period, Pangea started to break apart into two supercontinents: Laurasia and Gondwanaland. The continent split horizontally, and Laurasia (modern North America and Eurasia) became the northern half and Gondwanaland (modern Africa, South America, India, Antarctica and Australia) became the southern half.
Triassic Animal Life
The organisms (many water-dwelling) that were resilient enough to survive the Permian extinction didn’t hold out too long into the Triassic period. Many of them died out early on in the period. With these deaths, however, there was room for new life to burgeon. Ammonites (Triassic cephalopods) flourished during the early Triassic. A new type of cephalopod, a mollusk-type creature called a belemnite also came about, which is thought to be an ancestor of the modern squid.
Of course, the Triassic period is where the first reptiles and dinosaurs began to appear. Slowly but surely, cold- and warm-blooded reptiles emerged from the ocean, evolving into very diverse groups of creatures. And because of Pangea’s hot and dry climate, these creatures were very successful.
Both cold-blooded and warm-blooded reptiles existed during the Triassic period. Cold-blooded reptiles are thought to have been better suited to Pangea’s central climate, and the mammal-like reptiles, such as Therapsids, likely kept near the coastal areas. Mammalian creatures, though they appeared during the Triassic, wouldn’t be too evolutionarily successful until later periods.
Early dinosaur fossils have been dated back to the Triassic as well, though it’s important to distinguish that these creatures, and their future relatives, were warm-blooded, unlike modern reptiles. Their bones were structured differently, as well, especially in the hips, hands, and legs.
Reptiles likely dominated the Triassic oceans. These creatures were fully aquatic but had lungs instead of gills, equipped to breathe air instead of oxygen through water. Ichthyosaurs were popular creatures throughout the Triassic, and the end of the period appeared the plesiosaurs, a large, long-necked, and finned creature that continued to grow in number all the way through to the Cretaceous period.
The first flying reptiles came about during the late Triassic period, as well, and are identified as pterosaurs. Pterosaurs reached their prime much later, though, during the Jurassic and Cretaceous periods. It’s important to establish that these creatures aren’t likely relatives of modern birds; in fact, modern birds are more closely related to the dinosaurs rather than the flying reptiles.
Triassic Plant Life
Animal life wasn’t the only kind of life drastically affected by the late Permian extinction; many plants met their end during this crisis, too. During the Permian period, swamp and coastal plants really flourished, though when the mass extinction hit, these humidity-loving plants could no longer survive with the onset of the dry, hot Triassic climate.
Evergreen plants exploded in growth, able to accommodate for the dry heat. Conifers and ginkgos were not only able to survive the Permian extinction, but they thrived in the new environment.
The End of a Period
As the Triassic period came to an end, there was another extinction, though it was almost nothing compared to the 90 percent loss of the Permian extinction; this time, only about 20 percent of species met their end. For those that survived, they would rebound and come to rule over the two continents during the Jurassic and Cretaceous periods.
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