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Quaternary Period Facts and Timeline

Quaternary Period Facts and Timeline

The latest ongoing major geochronological time span―the Quaternary Period―shaped our planet to its present state of existence. Read this ScienceStruck article to gain more information about the major facts belonging to this period. The information provided below shall cover all the points, ranging from animals, plants, extinction events, etc.
Gaurav Athavale
Last Updated: Apr 20, 2018
Cycle of 25
The Dansgaard-Oeschger events are a series of cyclic climatic changes that took place twenty five times in the Last Glacial Maximum (LGM) or the last glacial period. The best recorded evidences have been studied in ice cores drilled in Greenland that date back to the Eemian interglacial (the last such interglacial before the present one).
The most recent time span of the Cenozoic Era, the Quaternary Period started about 2.5 million years ago (Ma), and is continuing till present date. A major chunk of this era is taken up by its first epoch called the Pleistocene, and only about 12,000 years make up the remaining portion called the Holocene epoch. Apart from environmental and climatic changes, the Quaternary Period is characterized by the evolution of modern animals and plants, along with the appearance of humans.

Giovanni Arduino coined the term 'Quaternary' in 1759, after the discovery of Po Valley alluvial deposits in Italy. Later in 1829, it was used to describe the sedimentary rocks in the Seine Basin of France, by Jules Desnoyers. This period is mainly known for the glaciation activity and associated Ice Ages, punctuated by short interglacials. The period started with an Ice age in the northern hemisphere, and various ancestral species of flora and fauna dominated the landscape (like saber-toothed tigers and mammoths).
Interesting Facts and Major Events of the Quaternary Period
Quaternary Period Timeline
quaternary period timeline

The Quaternary Period starts at the end of Neogene, and the boundary is marked by the Pliocene-Pleistocene Boundary Marine Extinction, which killed off a substantial number of marine organisms. Go through the timeline provided below to clearly understand the chronology of events in this period.


In the above image, it can be noted that the Quaternary Period is divided into two epochs, the larger one being Pleistocene, and the smaller one being Holocene. Pleistocene is further divided into four stages: Gelasian, Calabrian, Middle, and Upper. The Pleistocene Epoch started at around 2.5 Ma and ended at 0.01 Ma, after which Holocene epoch started and exists till present date.

Quaternary Period Geology and Tectonics
Though plate tectonics played a major role in changing the appearance of landmasses over the span of 2.6 million years, somewhat less change took place in terms of continental drifting and geology. Quaternary geological evidences and records of have been preserved in excellent condition all over the world, better than the other geochronological periods.

Tectonics started shaping up the continents as they were more or less similar in today's appearance. Landmasses were becoming more and more recognizable. The glaciers started retreating quickly. The Skagerrak and Bosporus straits formed the present day Baltic Sea and Black Sea, respectively. This was the major consequence of sea level rise due to melting of glaciers and influx of freshwater into already existing former marine water bodies.

A land bridge formed between the European landmass and the Britain mainland, due to the cyclic rise and fall of the water level in the English Channel. A similar geological process occurred in case of the Bering Strait, and the continents of Asia and North America were also connected by a land bridge. Extensive flooding took place in the northwestern regions of North America. The Great Lakes and the Hudson Bay formed as the Canadian cratonic regions underwent extensive tectonic upheaval.
pleistocene
present
Quaternary Period Climate and Environment
A typical periodicity regarding melting and formation of ice sheets can be seen in the Quaternary time span, and this can be attributed to several reasons, most notably the Milankovitch cycles. This led to significant intermittent changes in climatic and environmental parameters.

As this time is known for its periodic glaciations, the climate also changed accordingly from cold conditions to warm ones. But, the climate changed quickly enough to cause mass extinctions especially among the land fauna. Several species like the saber-toothed tiger, woolly mammoth, American cheetah, etc., became extinct at the end of Pleistocene.

Quaternary glaciations and the associated Ice Age can be said to be one of the most important identifiable characteristic this period, and evidences for the same have been preserved well all around the world. The glacial-interglacial cycles had a profound effect on the depositional environment of that time, when extensive erosion took place along with the formation of freshwater bodies. River and lake systems underwent some changes. The extensive ice sheets had an albedo effect (reflection of sunlight from a white surface), which lead to drastic drop in atmospheric temperatures. It is said that this event was caused due to the Milankovitch cycles, which explains the periodicity of solar intensity, which affects the Earth's climate.
Quaternary Period Era Fauna and Flora
In case of fauna, several species started thriving on land as well as in the sea. Many of them are the so-called ancestors of present-day animals. For example, today's tiger and elephant evolved from the saber-toothed tiger and mammoth, respectively. Go through the slide-show given below, which will present forth few examples of such fauna that lived in the Quaternary Period and are now extinct.
In case of flora, the dominance of angiosperms started in the Quaternary Period, leading to an increase in diversity of such plants due to favorable conditions. Many floral species were similar as compared to the present ones, and some have even escaped extinction to thrive in the current epoch.
Evolution of Man
As Prehistoric man first appeared during this time, it is also called the 'Age of the Humans'. The first modern humans evolved in the African subcontinent and were named as Homo erectus. In further generations, intelligence and other aspects improved along with bigger brains. It is said that this species first discovered the ways to hunt and also to make fire and find shelter. It is called erectus as it walked with an upright posture as compared to other previous members of this genus. Other species also existed like Homo neanderthalensisHomo habilis, and Homo sapiens.
Prehistoric Man Hunting Representation
Prehistoric Man Hunting Representation
Neanderthal Man
Neanderthal Man
Homo Erectus
Homo Erectus
Homo Habilis
Homo Habilis
Homo neanderthalensis existed on our planet from middle to late Pleistocene time span. They flourished across the European regions, and evidence suggests that they were almost non-existent in the African subcontinent. Homo habilis belonged to the Hominini tribe and existed few thousands of years before the Neanderthal man. Homo sapiens is to have evolved from the Neanderthal man. The name Homo sapiens sapiens is given to the current generation of humans who are highly intelligent as compared to the species that existed thousands of years ago.

Apart from hunting and discovering the use of fire, prehistoric man also evolved slowly and made different weapons and alternate ways of getting food, clothing, and shelter. He mostly expressed himself in the form of cave paintings, which are still remarkably preserved at some places on Earth.
Quaternary Period Extinction Events
Two main extinctions occurred during the Quaternary Period, and it is said that the second one is still ongoing. At the end of the Pleistocene, i.e. the Pliocene-Pleistocene boundary, the last glacial period or Ice Age started get over, leading to the extinction of many living beings. This was the first major mass extinction that took place in this period.

A reason for this event includes the high possibility of a nearby supernova explosion, which might have greatly affected the thin ozone layer of the Earth's atmosphere, causing extensive climate changes. Ice started to melt from as far as the Great Lakes region, and this gave the opportunity to many other mammals to thrive. Humans extensively evolved around this time. Insects, angiosperms or flowering plants, and mammals started dominating on the planet.
 
The second mass extinction is said to started about fifty thousand year, and supposedly is still going on. The evidences are in the form of disappearance of numerous large animals such as the woolly mammoth. Also, the rapid evolution of humans caused the rise of civilization, and man began to hunt down fauna for meat and other livelihood reasons. In some cases, due to over-poaching, entire species of fauna became extinct shortly. This is said to be one of the main reasons of the ongoing extinction event.
Uncertain Future
The current millennium and even the next few ones are said to be still under the Holocene epoch. But, if the Earth is amidst an interglacial time span according to research studies, then our planet might already be on the path towards another Ice Age, and possibly another large mass extinction event, where humans might suffer greatly. We absolutely have no idea about the future of our planet from a geological point of view in a broad manner, as the occurrence of any event is very uncertain.