We explain what the Permian period was, its relief structures and its climate. Also, what are its characteristics, its flora and fauna.
The Permian began about 290 million years ago.
What was the Permian period?
On the geological time scale, The Permian period is the last of the Paleozoic era, started 540 million years ago and finished approximately 248 million years ago. It is the period after the Carboniferous and before the Triassic, of the Mesozoic era.
The Permian began 290 million years ago and ended 248 million years ago. That is, it had a total duration of 42 million years. During this period, the Permian-Triassic mass extinction took place, the largest species disappearance event in the history of our planet Earth.
The continental crust at that time was united and formed a single supercontinent called Pangea.Initially, the climate was warm and humid, as in the Carboniferous, but as geological time passed, humidity decreased significantly and the planet became more arid.
The name of this period comes from the Russian city of Perm, where in 1841 the English geologist Roderick Murchison (1792-1871) identified and classified some fossils dating from that time.
Features of the Permian period
The main characteristics of the Permian period are:
- It began 290 million years ago and ended 248 million years ago.
- The continental crust was organized into a single supercontinent called Pangea.
- It had many climatic variations, from glaciations at the beginning to a warm and humid climate for much of the period.
- Some continental regions had a hot and dry climate.
- Its flora and fauna were very varied, both on the continents and in the oceans.
- It concluded with a great mass extinction of species, which eliminated virtually all animal life on Earth.
Division of the Permian period
The Permian is divided into three epochs or series, which cover nine ages or floors, as follows:
- Cisuralian period. It began about 298.9 million years ago and ended about 279.3 million years ago. It spans the Asselian, Sakmarian, Artinskian and Kungurian ages.
- Guadalupe era. It began about 272.9 million years ago and ended about 265.1 million years ago. It spans the Roadian, Wordian and Capitanian ages.
- Lopingian period. It began about 259.1 million years ago and ended about 254.2 million years ago, together with the Permian Period and the Paleozoic Era. It spans the Wuchiapingian and Changhsingian ages.
Geology of the Permian period
During the Permian period, Pangea was formed, a supercontinent composed of the union of all the land masses on the planet. Thus, most of the land masses formed a single block, which had a significant impact on the distribution of animal and plant species at that time.
In the Permian, the Hercynian or Variscan orogeny also occurred, as a result of the collision between the continents that formed Pangea. This produced the formation of mountains such as the Appalachian Mountains in North America and the Scandinavian Mountains in Europe.
Throughout this period, there were also episodes of significant volcanic activity., which released large quantities of gases and particles into the atmosphere. These volcanic events may have contributed to climate and environmental changes, as well as the mass extinction that occurred at the end of the Permian.
Climate of the Permian period
The Permian climate was influenced by the glaciations of the end of the Carboniferous period.so its initial conditions were very cold. Over time, the climate became warmer and wetter. As a result, the glaciers retreated and sea levels rose.
After the formation of Pangea, in addition, extensive regions remained far from the sea, which is why a hot, desert climate with great fluctuations between wet and dry seasons was also generated.
Towards the end of the Permian period, and as a consequence of the large amount of ash thrown into the atmosphere by intense volcanic activity, it is believed that the temperature decreased considerably. It is possible that the ash prevented the passage of the sun’s rays, so that the lack of light and heat could have been one of the causes of the mass extinction of species that occurred towards the end of the Permian.
Flora and fauna of the Permian period
The Nautilus has existed for 270 million years.
The extensive continental forests and jungles that formed in the Carboniferous period continued into the Permian, ensuring an oxygen-rich atmosphere. In the most humid areas, ecosystems with a warm and humid climate continued to form, while in the drier interior of Pangea, flora and fauna adapted to the lack of humidity began to appear..
Regarding the fauna, the insects evolved into their modern appearance and, since there were no aerial vertebrates yet, they were the ones who conquered flight. Furthermore, certain amphibians finished adapting to life outside of water and, at the end of the period, archosaurs appeared, which would give rise to crocodiles, pterosaurs and dinosaurs in the Triassic period.
In the seas, plankton managed to recover from the extinction of the Devonian period and life proliferated in nautiloids, echinoderms, mollusks and brachiopods. They were also developed fish primitive bones and sharkswhich were already announced as effective predators.
Towards the end of the period the mesosaurus, a reptile that lived on the present-day continents of South America and Africa. This species was fundamental evidence for the formulation of the Theory of Continental Drift that proposed the hypothesis of the movement of the continents.
Some of the living beings from the Permian period that left a sufficiently complete fossil record to this day are:
- The nautilus. Emerging in the waters of Micronesia, it is one of the few organisms that survived the extinction of the late Permian, and has changed very little in its 270 million year history of evolution. It is a round-shaped cephalopod mollusk, considered a living fossil.
- The dimetrodon. This now extinct genus of synapsid (mammal-like) reptiles had an enormous dorsal sail that consisted of elongated vertebral spines with membranous tissue between them.
- Ginkgo biloba. Another living fossil, this tree with yellow, double-leafed leaves first appeared 280 million years ago. Today it can reach 30 metres in height in its nearly thousand-year lifespan. Its leaves are used in medicinal recipes.
Permian-Triassic mass extinction
The extinction appeared to have been gradual, lasting up to 80,000 years.
The Permian period ends with the most significant mass extinction in the natural history of our planet.both in terms of the number of species lost and the impact on subsequent fauna. Only 5% of species survived: 96% of marine species and 99% of terrestrial species disappeared as a result of this great extinction.
The exact causes of such a mass extinction are unknown, but several hypotheses have been put forward:
- The contamination of the atmosphere with gases such as sulfur and carbon dioxide emanated by the action of volcanism.
- The impact of an asteroid, which could have had devastating consequences on the flora and fauna of the time.
- The release of hydrogen sulfide (a powerful toxic agent) into marine waters due to the proliferation of anaerobic bacteria due to the drop in oxygen.
- The emission of ash into the atmosphere due to the considerable increase in volcanic activity, which could have darkened the sky, with the consequent reduction in temperature and photosynthesis processes. This could cause an increase in the amount of carbon dioxide and a reduction in oxygen.
It is believed that the extinction may have been gradual, with a duration of between 80,000 and 200,000 years.
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