Neogene facts for kids
Quick facts for kids Neogene |
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| 23.04 – 2.58 Ma | |
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A map of Earth as it looked 15 million years ago during the Neogene Period.
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| Chronology | |
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Neogene graphical timeline
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Subdivision of the Neogene according to the ICS, as of 2024.
Vertical axis scale: Millions of years ago |
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| Etymology | |
| Name formality | Formal |
| Usage information | |
| Celestial body | Earth |
| Regional usage | Global (ICS) |
| Time scale(s) used | ICS Time Scale |
| Definition | |
| Chronological unit | Period |
| Stratigraphic unit | System |
| Time span formality | Formal |
| Lower boundary definition |
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| Lower boundary GSSP | Lemme-Carrosio Section, Carrosio, Italy 44°39′32″N 8°50′11″E / 44.6589°N 8.8364°E |
| Lower GSSP ratified | 1996 |
| Upper boundary definition |
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| Upper boundary GSSP | Monte San Nicola Section, Gela, Sicily, Italy 37°08′49″N 14°12′13″E / 37.1469°N 14.2035°E |
| Upper GSSP ratified | 2009 (as base of Quaternary and Pleistocene) |
| Atmospheric and climatic data | |
| Mean atmospheric O2 content | c. 21.5 vol % (108 % of modern) |
| Mean atmospheric CO2 content | c. 280 ppm (1 times pre-industrial) |
| Mean surface temperature | c. 14 °C (0 °C above modern) |
The Neogene (pronounced NEE-oh-jeen) is a long stretch of Earth's history. It lasted about 20.45 million years. This period began after the Paleogene Period and ended just before our current Quaternary Period. The Neogene is the second part of the Cenozoic Era, which is the era we live in today. It is also the eleventh period of the larger Phanerozoic Eon.
During the Neogene, life on Earth continued to change. Mammals and birds evolved into many of the forms we see today. The very first ancestors of humans, called Homo habilis, appeared in Africa towards the end of this period. Continents also moved, with one big event being the joining of North America and South America by the Isthmus of Panama. This changed ocean currents, making the Earth's climate much cooler over time. This cooling eventually led to the Ice Ages that followed. The name "Neogene" was created in 1853 by a scientist named Moritz Hörnes.
Contents
Exploring the Neogene's Time Divisions
The Neogene Period is split into two main parts, like chapters in a book about Earth's past. These parts are called epochs.
Each of these epochs is further divided into smaller time units. However, the Miocene and Pliocene are the main ones to remember for the Neogene Period.
How Earth's Continents Moved in the Neogene
During the Neogene Period, the continents looked very similar to how they do now. They were almost in their modern positions.
One exciting event was the formation of the Isthmus of Panama. This narrow strip of land connected North America and South America for the first time. The Indian subcontinent also kept pushing into Asia, which helped to build the towering Himalayas mountains even higher. As sea levels dropped, natural land bridges appeared. These bridges connected Africa to Eurasia and Eurasia to North America, allowing animals to travel between continents.
Understanding Neogene Climate Changes
The Earth's climate during the Neogene became more varied, with clearer seasons. It also continued a general trend of getting drier and cooler. This trend had started in the previous Paleogene Period.
The early part of the Miocene Epoch was quite cool. However, during the Middle Miocene, Earth experienced a warmer time. Later, around 11 million years ago, the climate cooled down again. Ice caps at both the North and South Poles began to grow larger and thicker. This process made the Earth even colder.
During the Pliocene Epoch, there was another warm period. Scientists study this time to understand how Earth's climate might change in the future. Towards the end of the Neogene, the Earth cooled significantly. This led to the start of the Ice Age that followed.
Amazing Animals and Plants of the Neogene
Life in the oceans and on land during the Neogene started to look very much like it does today. Some ancient reptile groups disappeared early in this period. Other amphibians also vanished by the end.
The oceans were home to huge predators. These included giant sharks like megalodons and massive whales called livyathans. About 19 million years ago, many types of open-ocean sharks disappeared.
On land, mammals and birds were the main animals. They adapted to many different places and evolved into new forms. For example, grazing animals like horses in North America became faster runners. This helped them survive in the new open grasslands. Bears also diversified quickly during this time. Most importantly, the first hominins, who are the ancestors of humans, appeared towards the end of the Neogene.
Around 20 million years ago, gymnosperms, which include conifers and cycads, began to develop more species. This was due to the changing climate. As the Earth became cooler and had more distinct seasons, tropical plants were replaced by deciduous trees that lose their leaves. Vast forests also turned into wide grasslands.
Grasses became very diverse, and many plant-eating mammals evolved to graze on them. This led to the development of animals like horses, antelope, and bison that we know today. In the Pliocene, large Ice Age mammals such as mammoths and woolly rhinoceros were common. Certain types of grasses became very common in grasslands as carbon dioxide levels in the atmosphere changed. Even daisies (part of the Asteraceae family) developed many new species. Interestingly, fossil leaves of Eucalyptus trees have been found in New Zealand from the Miocene, even though these trees are not native there today.
See also
In Spanish: Neógeno para niños
