Within the Paleozoic era there are 6 periods in which geological time is divided. During the Permian period, located between the carboniferous and Triassic, life developed with great changes. Permian fauna it had as its protagonist the first sketch of mammals as well as the diversification and expansion of other living beings that already existed. The Permian period lasted approximately 48 million years and was considered a time of transition for the planet both at a geological and climatic level.
In this article we are going to tell you about the characteristics and evolution of the Permian fauna.
Permian period
There are many specialists who repeatedly investigate this period since a large amount of valuable information can be obtained. Especially at the end of the Permian it is of scientific interest since it was presented the most catastrophic and devastating mass extinction event on the entire planet. This process of mass extinction was more important than the extinction of the dinosaurs in the cretaceous.
The period of extinction became known as "the Great Dying" and in it More than 90% of all species of living beings have disappeared. Only a few species survived which gave way to other more famous animals in the history of the earth such as dinosaurs. The total duration of the Permian is estimated at 48 million years, beginning 299 million years ago and ending 251 million years ago.
During this period, the climate was quite variable. Ice ages occurred at both the beginning and end of this period, and the climate was quite warm and humid during its intermediate phase.
The Great Dying in the Permian fauna
During this period some species of animals came to experience great diversification. In this case, we find a great evolution in reptiles that were considered as mammals. And it is that in some fossil records the ancestors of current mammals could be found. That is to say, current mammals come from the reptile.
With respect to the Great Dying constituted one of the most important mass extinction events on the entire planet. It occurred throughout this period already at its end almost at the beginning of the Triassic period. It is the most devastating extinction process the entire planet has ever gone through. And it is that 90% of the species of living beings that populated the planet became extinct. The causes of this mass extinction are not fully known, but there are some theories that try to postulate what happened.
Among the theories most affected is that of a intense volcanic activity that caused the expulsion of large amounts of carbon dioxide into the atmosphere. As we know, carbon dioxide is a greenhouse gas with the ability to retain heat. The large amount of carbon dioxide released into the atmosphere caused an increase in average ambient temperatures. This led to global atmospheric instability, and many living beings were unable to adapt to the environmental conditions.
Another proposal is the cause of the release of hydrocarbons from the ocean floor and the impact of a meteorite. Whatever the cause of it, it is a very catastrophic event that greatly affected all the environmental conditions that existed on the planet at that time.
Permian fauna
During this period, some species of animals that originated in previous periods were kept. However, an important group of new animals such as were the mammalian reptiles. These animals are considered ancestors of current mammals. A very diverse life was found in the seas.
invertebrates
Among the invertebrates that stand out among the Permian fauna, some marine groups stand out, such as echinoderms and mollusks. Thanks to various scientific studies, fossil records of bivalves and gastropods, as well as some brachiopods, have been found. Within this group and within marine ecosystems, members of the Porifera phylum, which includes sponges, stand out. These animals were the originators of many of the barrier reefs.
Despite the fact that most of these animals became extinct, a fossil record has been found in which more than 4 thousand species have been distinguished. Their distinctive characteristic was that these animals were protected by a covering of calcareous material. On the other hand, arthropods, especially insects, developed well, as in previous periods. It should be noted that insects were somewhat larger in size than today. Several new orders appeared in this group of animals, such as Diptera and Coleoptera.
Vertebrates
Turning to the vertebrates, we see that they also underwent a significant expansion and diversification, both in terrestrial and aquatic ecosystems. Fish were the most representative animals of this period. Here we find chondrichthyans, such as sharks and bony fish. One of the sharks that became extinct during the Cretaceous period was already living at this time. The sharks of that time were very similar to those of today, although not very large. They could only reach 2 meters in length.
We also see the Orthacanthus. This is a type of fish that is now extinct. It belongs to the shark group and its appearance was quite different. Its body resembled that of an eel and it had several types of teeth. We also have amphibians. These animals underwent development. They were a quite diverse group and could range in size from a few centimeters to 10 meters.
Finally, we see that reptiles were the animals that presented the greatest diversification. Among these reptiles we find therapsids, which were a group of mammals considered as the ancestors of today's mammals. Among their distinctive characteristics, we found that they presented several types of teeth and each one was adapted to different functions. In addition, they had 4 limbs or legs and their diet was varied. There were both carnivorous and herbivorous species.
I hope this information helps you learn more about the Permian fauna.