The Cenozoic era was divided into various periods and, in turn, into various epochs. Today we are going to talk about the second period of this era and it is the Neogene. It began about 23 million years ago and ended 2.6 million years ago. It is a period where the planet experienced a series of changes and transformations at the geological level and in terms of biodiversity. One of the most significant events in this important period is the appearance of Australopithecus, one of the main ancestral species of the Homo sapiens.
In this article we are going to tell you everything you need to know about the Neogene and its importance in geology.
Key features
The Neogene stage was the one in which our planet experienced high geological activity both in relation to the continental drift as at sea level. And is that the continents continued their displacement to the positions they currently occupy due to that movement of plate tectonics caused by the convection currents of the Earth's mantle.
Due to this movement of the continental plates, maritime activity also changed. Ocean currents were modified as certain types of physical barriers emerged, and wind patterns shifted due to climate change. This event was quite significant as it had an immediate impact on Atlantic Ocean temperatures. One of the most important physical barriers that arose from this plate movement was the Isthmus of Panama. In addition, during this period, one can observe the geological features that resulted in the formation of the Betic system, which is relevant to understanding Neogene geology.
During this period, biodiversity also developed quite extensively. Terrestrial mammal groups were those that underwent the greatest transformation. On the other hand, birds, reptiles, and the marine environment also enjoyed great evolutionary success, reflecting the richness of the Neogene fauna.
Neogene Geology
As we have mentioned before, this is a period where there is high geological activity from the orogenic point of view and from the point of view of continental drift. The fragmentation of Pangea continued and the various fragments that originated began to form a displacement in different directions.
During this period, several land masses collided with southern Eurasia. These land masses were North Africa and India. India was not a part of the continent that had its own continental drift, but was instead pressed against Eurasia. This is how the continental masses rose and formed the orogeny that today we know as the Himalayas.
The formation of the Isthmus of Panama had immediate consequences, resulting in significant temperature fluctuations across the planet. More specifically, it affected the temperatures of the Pacific and Atlantic Oceans, causing them to decline. In this geological context, we can understand how the climate influenced the development of various ecosystems, as described in our entry on the ice ages.
Climate
Regarding climate, during this period, our planet was primarily characterized by a global drop in temperature. Above all, The territories that were located in the northern hemisphere had a slightly warmer climate than those located at the South Pole. Similarly, the climate has changed over time, as have existing ecosystems. These changes in ecosystems are due to evolutionary adaptations to the new environmental conditions offered by a changing world.
In this way, the large expanses of forest failed to evolve and adapt to the new environmental conditions, so they disappeared, giving way to ecosystems where prairies and savannas predominated, with a large number of herbaceous plants. Throughout this period, the planet's poles were completely covered in ice, just as they are today. The ecosystems that predominated were those with vegetation made up of a large number of herbaceous plants, whose most representative trees were conifers. This climate change and the configuration of the lands appeared in the Miocene, which is important for understanding long-term evolution.
Neogene flora
During the Neogene, there was an expansion of the life forms that had existed since the Paleogene. The Earth's climate and temperatures had a great influence on the development and establishment of new living beings. The evolution of adaptation to these environments was able to create new life forms. The fauna experienced the greatest diversification, as the flora remained somewhat stagnant due to the global drop in temperatures.
The flora was limited by the climate since the development of jungles or forests with large extensions was limited and even caused large hectares of them to disappear. Since the great forests and jungles could not be found with such low temperatures, Plants were developed that could adapt to an environment with low temperatures, such as herbaceous plants. This led many specialists to refer to this period as "the age of herbs." In this context, some similarities can be observed with the , which also evolved under these conditions.
Some specialists refer to this time when they point out at the flora level as »The age of herbs». Not for this reason, many species of angiosperms were able to establish and develop successfully.
Fauna
Regarding the Neogene fauna, we can see a wide diversification of many of the animal groups we know today. The most successful groups were reptiles, birds, and mammals. We cannot forget the marine ecosystems, where the cetacean group also underwent great diversification. To understand the impact of these species, it is advisable to review the fauna of the Miocene and the Pliocene.
Birds of the order Passeriformes and the so-called "terror birds" were found primarily in the American continent. Today, birds of the order Passeriformes are the most diverse and extensive group of birds. This is because they have managed to survive for so long and are characterized primarily by their feet, which allow them to perch on tree branches. Furthermore, they have the ability to sing, which leads to complex mating rituals.
Of the mammals we can say that it is the one that underwent a wide diversification. All the Bovidae family from which goats, antelopes, sheep and, on the other hand, those of the Cervidae family belong, where deer and stags belong expanded their distribution enormously. When studying these groups, it is interesting to observe how their evolution is connected to the conditions of the and the , stages that also influenced their development.
The group of mammals that marked an extremely important event in the entire evolutionary process was that of the first hominid. It is the Australopithecus and is characterized by its small size and its bipedal movement.
