To understand what era is now, you need to look at the decision of the II session of the International Geological Congress, held in 1881. Then scientists argued about the geological chronology of our planet. There were several points of view that confused science. By a general vote of experts, it was decided that the modern geological era is Cenozoic. It began 66 million years ago and continues to this day.
Cenozoic features
Of course, the modern geological era is not something monolithic and monotonous. It is divided into three periods: Paleogene, Neogene and Quaternary. During this time, the world has changed dramatically. In the early stages of the Cenozoic, the Earth looked completely different from what it is today, including in terms of flora and fauna. However, just then, several events occurred, as a result of which the planet became the way we know it.
The restructuring of the worldwide system of interconnected sea currents has begun. It was caused by an unprecedented continental drift. Its consequence was the complication of heat transfer between the equatorial and polar basins.
Continental drift
The Gondwana supercontinent split in the Paleogene. An important event that marked the modern geological era was the clash of India and Asia. Africa from the south-west "stuck" in Eurasia. So the southern mountains of the Old World and Iran appeared. Geological periods proceeded slowly, but the map of the Earth inexorably became similar to today's.
The ancient Tethys Ocean, which separated northern Laurasia and southern Gondwana, disappeared over time. Today, only the seas (Mediterranean, Black and Caspian) remain of it. Important events also took place in the southern hemisphere. Antarctica broke away from Australia and headed towards the pole, turning into a glacial desert. The Isthmus of Panama appeared, which connected South and North America, finally dividing the Pacific and Atlantic oceans.
Paleogen
The first period, which opened the modern geological era, is the Paleogene (66-23 million years ago). A new stage in the development of the organic world has begun. The boundary of the Mesozoic and Cenozoic was marked by the mass extinction of a huge number of species. Most people know this catastrophe from the extinction of dinosaurs.
The Mesozoic inhabitants of the Earth were replaced by new mollusks, bony fish and angiosperms. In previous geological periods, reptiles dominated on land. Now they have lost the lead to mammals. Of the reptiles, only crocodiles, turtles, snakes, lizards and some other species have survived. The modern appearance of amphibians has formed. The air was dominated by birds.
Neogene
The generally accepted sequence of geological eras states that the second period of the Cenozoic era was Neogene, which replaced the Paleogene and preceded the Quaternary. It began 23 million years ago, and ended 1.65 million years ago.
At the end of Neogene, the organic world finally accepted modern features. Discocyclines, assilins and nummulites became extinct in the sea. The composition of the organic world on land has changed dramatically. Mammals adapted to life in the steppes, dense forests, semi-steppes and semi-deserts, thus colonizing vast territories. It was in the Neogene that proboscis, ungulates, and other representatives of the fauna common today (hyenas, bears, martens, badgers, dogs, rhinos, sheep, bulls, etc.) appeared. Primates emerged from the forests and populated open spaces. 5 million years ago, the first ancestors of a modern hominid man appeared. In the northern latitudes, heat-loving forms of flora (myrtle, laurel, palm trees) began to disappear.
The formation of modern mountains and seas
In Neogene, the process of mountain building continued, which determined the modern landscape of the planet. In America, the Cordilleras and Appalachians formed, in Africa - the Atlas. Mountains appeared in the east of Australia and in Hindustan. In the western Pacific Ocean, marginal seas (Japan and Okhotsk) arose. Volcanoes were distinguished by activity, volcanic arcs rose from the water.
For some time, the level of the oceans exceeded the present, but by the end of the Neogene it fell again. Glaciation swept not only Antarctica, but also the Arctic. The climate became increasingly unstable and contrasting, which was especially characteristic of the next Quaternary.
Fauna migration
In the Neogene period, the territories of the Northern Hemisphere were finally united into an integral space. There was a Mediterranean way between Africa and Europe. The Turgai Sea disappeared in the West Siberian Lowland. It separated Europe from Asia. After drying, the migration between different parts of the world was facilitated. Herbivorous horses came from America, and antelopes and bulls from Asia. Trunks spread outside of Africa. Cats, which at first were saber-toothed and lived only in America, flooded Eurasia.
4 million years ago, the Isthmus of Panama arose. There was a land connection between the two Americas, which led to an unprecedented migration of animals. The southern fauna throughout the Cenozoic was in a state of isolation, actually inhabiting a huge island. Now, species unfamiliar to each other came into contact. The fauna has mixed up. Armadillos, sloths and marsupials appeared in the north. Horses, tapirs, hamsters, pigs, deer and camelids (llamas) colonized South America. The northern fauna was enriched. But in South America there was a real disaster. Due to new competitors represented by ungulates and predators, many rodents and marsupials died out. These controversial events came to be called the Great American Exchange.
Quaternary
It took several billion years for numerous geological eras and periods to succeed each other and finally come to the point when the Quaternary Cenozoic began a half million years ago. It continues to this day, so it can be considered modern.
All periods and eras of geological history are distinguished from each other by unique features. The Quaternary is also called an anthropogen, since it was during this period of time that the development and formation of man fell. His first ancestors appeared in East Africa. Then they settled Eurasia, and from modern Chukotka came to America. People have gone through several stages of development. The last (intelligent man) came 40 thousand years ago.
However, the Quaternary is unique in its climatic leaps. Over the past million years, several ice ages have passed, changing to warming. Climatic troubles led to the extinction of many heat-loving species of flora and fauna. The animals that adapted to life in the conditions of the ice age (mammoths, woolly rhinos, saber-toothed tigers) also disappeared.
Holocene
The answer to the question, what era is now, has already been found (Cenozoic). At the same time, the Quaternary period continues today. It is also divided into parts. The modern section of the Quaternary is the Holocene era. It began 12 thousand years ago. Scientists call it interglacial. That is, this is the period that has come after significant warming.
At the same time, modern mankind has managed to catch several small ice ages. Climatic changes characteristic of the entire Quaternary period over the past 12 thousand years have been cyclically repeated several times. At the same time, in terms of scale, it remains miniature and not so cardinal. Climatologists note a small ice age, which occurred in 1450-1850. Winter temperatures in Europe have dropped, leading to frequent crop failures and shocks in the agricultural economy. The Little Ice Age was preceded by the Atlantic Optimum (900–1300). During this period, the climate was noticeably milder, and glaciers were significantly reduced. It should be remembered that the Vikings, who discovered Greenland in the Middle Ages, called it the “green country”, although today it is not at all “green”.