A Cenozoic EraIt's a geological era belonging to the Phanerozoic Eon and which began 65.5 million years ago, extending to the present. It is divided between the Paleogene and Neogene periods, the latter being the most recent. Each of these periods is subdivided into epochs, from the Eocene to the current epoch, called Holocene.
During the Cenozoic Era, planet Earth acquired its current characteristics of climate, relief and continental distribution, in addition to its biological composition. It was also in the most recent period of the Cenozoic Era that human beings emerged, becoming important agents of transformation of the natural environment.
Read too: Mesozoic Era — details about the geological era that preceded the Cenozoic Era
Topics in this article
- 1 - Summary of the Cenozoic Era
- 2 - What is the Cenozoic Era?
- 3 - Background of the Cenozoic Era
- 4 - Characteristics of the Cenozoic Era
-
5 - Periods of the Cenozoic Era
- → Paleogene (65.5 to 23 million years)
- → Neogene (23 million years to the present)
- 6 - End of the Cenozoic Era
- 7 - Geological time scale
- 8 - Solved exercises on the Cenozoic Era
Summary about the Cenozoic Era
The Cenozoic Era is a geological era that began 65.5 million years ago and continues to the present day. It belongs to the Phanerozoic Eon.
It is divided into two periods: Paleogene (65.5 to 23 million years) and Neogene (23 million years to the present).
Each period of this era is divided into epochs, which are: Eocene, Oligocene, Miocene, Pliocene, Pleistocene and Holocene.
It is preceded by the Mesozoic Era, marked by the emergence and extinction of dinosaurs, the diversification of animal and plant species on Earth and the beginning of the fragmentation of Pangea.
It is characterized by the succession of ice ages, in addition to the latest tectonic movements that caused the continents to acquire their current configuration.
During the Cenozoic Era, new species of animals developed and spread across the planet, such as large mammals and primates, while others became extinct.
Human beings emerged during the Neogene Period of the Cenozoic Era. As a result, human activity became an important agent of transformation of the natural environment.
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What is the Cenozoic Era?
The Cenozoic Era is the geological era in which we find ourselves at present It isstarted 65.5 million years ago. It belongs to the Phanerozoic Eon and began shortly after the end of the Mesozoic Era, with the end of the Cretaceous Period. Planet Earth as we know it today and all the elements that characterize it, such as climate, vegetation, relief and different forms of life, were established during the Cenozoic Era. Among the forms of life, human beings stand out.
The word Cenozoic has its origins in Greek and means “new life” or “new forms of life”, making reference to the biological diversification that planet Earth has undergone since the beginning of this era geological.
Like the other geological eras of the Phanerozoic, the Cenozoic Era is divided into two periods. These periods are known as:
Tertiary (65.5 to 1.8 million years).
Quaternary (1.8 million years to the present).
The periods of the Cenozoic Era, however, were reevaluated and, today, are divided into:
Paleogene (65.5 to 23 million years), therefore, inserted in the ancient Tertiary Period.
Neogene (23 million years to the present), this new period comprises part of the ancient Tertiary and all of the ancient Quaternary.
Background to the Cenozoic Era
The Cenozoic Era occurred after the Mesozoic Era, which was between 251 and 65.5 million years in the geological past. The geological era that preceded the Cenozoic became known as the era of reptiles, as it was during it that new specimens of this class of animals emerged, resulting in a great diversification of species and types. It was even during the Mesozoic Era that they emerged and became extinct. the dinosaurs. These giant reptiles began to appear on Earth in the Triassic Period, reached their peak in the Jurassic and became extinct at the end of the Cretaceous.
During the Mesozoic Era, two major mass extinctions occurred, which led to a new process of repopulation and differentiation of animal and plant species existing on planet Earth. These extinctions happened during the Permian Period and during the Cretaceous, that is: at the beginning and end of the Mesozoic Era.
It was also before the Cenozoic Era that Pangea (supercontinent that reuall the masses emerging from the Earth) finished being formed and began to fragment. This means that it was during the Mesozoic that the continents we know today began their formation process to acquire their current configuration. Furthermore, Pangea's climate was hot and dry, which created a series of desert regions. The exception was the lands close to the Earth's Equator, which had a higher moisture content.
Characteristics of the Cenozoic Era
The Cenozoic Era There is an initial milestone, but it is not yet finished. The era in which we live is the last on the geological time scale and began 65.5 million years ago, shortly after the end of the Cretaceous Period and the extinction of the dinosaurs. The main aspect of the Cenozoic Era is that the characteristics of planet Earth started to show itself right at the beginning, more than 65 million years ago, which includes the configuration of the continents, the types of climate and the different forms of life.
It all started with the fragmentation of the supercontinents, which represented the emerged lands, giving rise to the continental forms as we know them today. There was also the emergence of new species of animals, insects, fish and plants, with great evolution and diffusion of mammals. It was during the Cenozoic Era that primates appeared and developed.
Considering the breadth of the geological scale, we can say that, more recently, the Cenozoic Era was marked by the emergence of Homo sapiens and for constitution of different groups of collecting and hunting individuals on the Earth's surface, giving rise to human populations and, later, to the different societies that coexist on our planet.
Periods of the Cenozoic Era
The Cenozoic Era is divided into two distinct periods, which we will discuss below. Each is subdivided into seasons.
→ Paleogene (65.5 to 23 million years)
Paleogene Epochs | |
Paleocene (65.5 to 55.8 million years) |
Warm and uniform climate across the planet, with the continued separation of continents, some already with a shape similar to the current one. After a mass extinction in the Cretaceous, small mammals, reptiles, and rodents emerged or developed and spread. Primates originated during the Paleocene. |
Eocene (55.8 to 33.9 million years) |
The temperatures during this period were the highest recorded for the Cenozoic Era. The high level of the oceans caused sea water to advance over the continents. In this case, whales, elephants, bats and animals with hooves, such as short horses, appeared. |
Oligocene (33.9 to 23 million years old) |
Antarctica began to become an isolated continent, at the same time as the ice sheet over it expanded for the first time. Tectonism and volcanism have become more intense in areas such as North America, parts of South America and Europe. While some animal species adapted and developed to the new, now seasonal climate, others became extinct. |
→ Neogene (23 million years to present)
Neogene Epochs | |
Miocene (23 to 5.3 million years old) |
Mountains and mountain ranges formed or continued to rise during the Miocene, such as the Himalayas and Appalachians. The Earth's climate cooled, and new biomes emerged, such as the Prairies and Steppes, formed by tall grasses and low vegetation. Large mammals were predominant at this time, and anthropoid primates, the closest to the human species, appeared. |
Pliocene (5.3 to 1.8 million years) |
Earth's climate cooled during the Pliocene, and polar ice caps in the Southern Hemisphere continued to grow. Additionally, an ice cap appeared at the North Pole. Almost all of the continents already had their current shape, and the Mediterranean Sea had dried up at that time. The migration of animals across land bridges was intense, at the same time that new species of mammals emerged. There was the development of the first hominids. |
Pleistocene (1.8 million to 10,000 years) |
Changes in climate were felt throughout the Pleistocene, which had periods of glaciation and interglacials, which altered ice cover and ocean levels. Because of these variations, many species of animals and plants ceased to exist, as was the case with large mammals (mammoths, mastodons, saber-toothed tigers and others). Modern human beings began to inhabit a large part of the emerging lands, with the exception of the poles and Antarctica. |
Holocene (10,000 years to present) |
Planet Earth acquired the climatic, continental and biological configuration that we know. At the same time, human beings have become one of the main agents transforming natural space and the environment in which they live. There are researchers who, because of this, add the Anthropocene Period right after the Holocene, indicating that it is a time in which the presence and action of human beings on natural agents (atmosphere, biota and relief) are predominant on planet Earth, as well as determining the transformations on it observed. |
See too: Mammoth — details about a large mammal extinct in the Cenozoic Era
End of the Cenozoic Era
The Cenozoic Era is the current geological era, that is, it is the era in which we live. She yet it is in progress, and there is no defined period for its end.
Geological time scale
The geological time scale is the timeline that records the process of transformation and evolution of planet Earth from its origin, 4.6 billion years ago, to the present. It is a time scale measured in billions, millions or thousands of years, divided as follows:
Aeons: longer time intervals, measured in billions and millions of years.
Geological eras: subdivisions of eons, counted in millions of years.
Periods: subdivisions of geological eras, counted in thousands or millions of years.
Seasons: subdivisions of geological periods, being the shortest interval on the geological scale.
Also access: What is the origin of life?
Solved exercises on the Cenozoic Era
Question 1
(UFRGS) Consider the following statements about the Quinary geological period.
I. In the period beginning after the Quaternary, human actions on the Earth's surface imply the recognition of surface deposits and anthropogenic landforms.
II. In the current geological period, man is an important geological agent on the planet and triggers geomorphological processes whose intensities surpass many natural processes.
III. Given the projections of the scarcity of non-renewable natural resources, the name Quinário, for the current period of recognition of man as a geological and geomorphological agent, will be proposed from the end of the next century.
Which are correct?
A) Just I.
B) Only II.
C) Only III.
D) Only I and II.
E) I, II and III.
Resolution:
Alternative D
Human transformations in the Quaternary (currently called Neogene) were fundamental to the process of transformation of various aspects of planet Earth. The Quinary terminology is already used by some researchers to refer to this period, while others call it the Anthropocene.
Question 2
(IGF) Planet Earth is about 4.5 billion years old. For study purposes, this entire period is divided into eons, eras and periods. The Phanerozoic eon is subdivided into the Paleozoic, Mesozoic and Cenozoic eras.
Considering knowledge about the history of planet Earth and the evolution of life, it is correct to say that human beings arise:
A) in the Cenozoic era.
B) in the Jurassic period.
C) in the Mesozoic era.
D) in the Triassic period.
E) in the Paleozoic era.
Resolution:
Alternative A
Humans emerged during the late Pliocene Period, in the Cenozoic Era.
Sources
ESSAY. What is the Anthropocene and why does this scientific theory hold humanity accountable? National Geographic Brazil, 16 Jan. 2023. Available in: https://www.nationalgeographicbrasil.com/historia/2023/01/o-que-e-o-antropoceno-e-por-que-esta-teoria-cientifica-responsabiliza-a-humanidade.
TEIXEIRA, Wilson.; FAIRCHILD, Thomas Rich.; TOLEDO, Maria Cristina Motta de; TAIOLI, Fabio. (Eds.) Deciphering the Earth. São Paulo, SP: Companhia Editora Nacional, 2009, 2nd ed.
YOUTH AND EDUCATION IN SCIENCE (YES). Cenozoic. United States Geological Survey (USGS), [n.d.]. Available in: https://www.usgs.gov/youth-and-education-in-science/cenozoic.
Would you like to reference this text in a school or academic work? Look:
GUITARRARA, Paloma. "Cenozoic Era"; Brazil School. Available in: https://brasilescola.uol.com.br/geografia/era-cenozoica.htm. Accessed on November 10, 2023.
