Cenozoic era

The Cenozoic era was the third of the major epochs in earth’s history, beginning approximately 66 million years ago and extending to the present. It was the time interval during which the continents assumed their modern configuration and the different geographical positions that they maintain to this day and during which the flora and fauna of the earth evolved to reach the current ones. The term Cenozoic, originally spelled Kainozoic, was introduced by the English geologist John Phillipsin an 1840 Penny Cyclopaedia article and used it to name the most recent of the three major subdivisions of the Phanerozoic Aeon .

What happened in the Cenozoic era

During this era, the Atlantic Ocean expanded forming the Atlantic mountain range , countries like India , had great shocks until they came to form the Himalayas , at the same time the African tectonic plate made its movements towards Europe forming the Alps , and in North America the Rocky Mountains were formed by the same processes . The Cainozoic rocks develop in continents, particularly lowland plains and harder acquired by the high pressure caused by deep burial , the chemical diagenesis andhigh temperatures . Sedimentary rocks predominated during the Cenozoic, and more than half of the world’s oil is located in them.

Characteristics of the Cenozoic era

The main characteristics that stood out during the Cenozoic era are:

• The mammals evolved and diversified.
• There was extension of the fauna throughout the entire earth.
• The Atlantic Ocean expanded.
• The great mountain ranges of the world were born.
• The first hominids appeared .
• The polar caps were formed .
• The human species appeared .

Cenozoic era periods

The Cenozoic era is divided into two periods called Tertiary and Quaternary , which in turn are subdivided into different periods.

Tertiary Period

It is the first period and the forms of life both on land and in the sea were similar to those of today. Dinosaurs had already disappeared and mammals and birds ruled the land. There were marsupials, herbivorous and insectivorous animals, ruminants and whales. This period is subdivided into five epochs:

• Paleocene : There was a cooling of the planet and the Pangea finished dividing. Greenland moved away from North America and many species of birds emerged along with angiosperms .
• Eocene : Great mountain ranges arose that caused the orogeny . Mammals became the most important animals and the first horses appeared. Primates were born and some mammals adapted to marine life .
• Oligocene : Tectonic plates continued to collide and the Mediterranean was formed . The Himalayan mountains and the Alps were formed . There were large numbers of rodents and mammals.
• Miocene : The Alps, Himalayas and the mountain ranges of America were completed. An Antarctic ice cap formed , making the climate cooler outside of Antarctica. Grasslands originated and fauna evolved.
• Pliocene : Mammals reached their peak and spread, the climate was cold and dry and hominids appeared with different species such as Australopithecines and Homo habilis / homo erectus , ancestors of Homo sapiens .

Quaternary Period

This period is divided into two different stages:

• Pleistocene : also called the ice age because it spread over a quarter of the earth’s surface, in places where there was no ice, the flora and fauna were the same as those of the previous period called Pliocene. By the end of the period many mammals had become extinct .
• Holocene : in this period the ice disappeared giving rise to large areas of land and widening the continental shelf . The climate was warm with an abundance of flora and fauna . Human beings began to unite in groups and began to use hunting and agriculture to survive, leaving life as nomads abandoned .

Weather

Cenozoic was considered a period of cooling that lasted a long time. At the beginning of the Cenozoic period, many particles blocked solar radiation.  After Australia completely separated from Antarctica during the Oligocene period , the climate cooled considerably due to the appearance of the Antarctic Circumpolar Current that produced an enormous cooling of the Antarctic Ocean . Then, during the Miocene there was a slight warming due to the release of hydrates that released carbon dioxide. The climate cooled down and the first ice ages appeared .

Cenozoic era animals

At this stage the extinction of the dinosaurs and many species of the time occurred. It is assumed that this happened due to the impact of a large meteorite that raised large amounts of dust preventing light from reaching the plants and causing serious alterations in the food chain, resulting in the extinction of 75% of life. The mammals took advantage of the situation and reproduced dominating and the earth .

Floors

The Flora of the Cenozoic era was characterized by the development of such plants flowering plants and trees of foliage . There was a great variety of plants and trees that dominated the landscapes. These plants were angiosperm types and they developed and adapted easily to the weather conditions that existed at the time. Fruit trees , palms and legumes could be found in the Cenozoic era.