The term “Quaternary” (i.e., “Fourth”) was proposed by Jules Desnoyers in 1829 to describe certain sedimentary and volcanic deposits in the Seine Basin in northern France and was made official by Morlot in 1854. Although these deposits contained few fossils, Desnoyers was convinced on the basis of field studies that these deposits were younger than the Tertiary series of rocks.
In 1839, the great Scottish geologist Charles Lyell divided the Quaternary period into the older Pleistocene ("most recent“) composed primarily of glacial deposits and the younger, more recent Holocene (“completely recent“) which is the Period we are in which we live.
In 2000, the Nobel Prize winning atmospheric chemist Paul Crutzen proposed the adoption of a new geological Epoch call the “Anthropocene” to represent the most recent period in the Earth's history in recognition of the significant influence of human behavior on the Earth in recent decades. The Anthropocene has no precise start date but is considered to have begun in the late 18th century when the activities of the humans first began to have a significant global impact on the Earth's climate and ecosystems.
Tectonics and Paleoclimate
During the Pleistocene, the most recent Ice Age hit which was a series of advances and retreats of the ice as the climate fluctuated between cold (glacial) and warm (interglacial) periods. The sea level rose during the melting of the glaciers, and then dropped again during the next long cold spell (ice formation). The lowered sea levels formed land bridges that enabled the migration of animals and humans across continents.
The Holocene is characterized by climatic warming and the beginning of the present interstadial (i.e., warming period between glaciations). It is interesting to note that all other ages, epochs, and eras are represented by natural evolutionary and geological phenomena whereas the Holocene is distinguished by human activities and geographical impacts such as the continual and unrestrained rise of cities, towns, fields, and roads and a corresponding exponential growth in human population and knowledge.
The Anthropocene essentially represents the 18th Century to present beginning with the “Industrial Revolution” and characterized by Western imperialism and assimilation, secularism, mass media, and a global society.
The flora during the Quaternary is essentially what is found today except for those species which have been affected by climate changes during the Pleistocene and human expansion during the Holocene and Anthropocene.
During the beginning of the Quaternary, mammalian forms were at its height with both small and giant animals living alongside each other. Most animals were basically modern species but there were also a variety of giant mammals (a.k.a., “megafauna”) which evolved including giant kangaroos and wombats in Australia, mammoth and woolly rhinos in Europe, mastodon, camels, and dire wolves in America, and elephant-sized ground sloths as well as giant armadillo-like creatures called glyptodonts in South America.
The hominid tendency to increase brain size and hence intelligence continued giving rise to Homo erectus, Homo neanderthalensis, and finally modern man (Homo sapiens). Language evolved and with it came the sharing of knowledge, concepts and ideas. It is unknown exactly when language came into existence and it is highly debated as to whether or not the neanderthal possessed this capability.
Meteorite Impacts on Earth
I included a list of meteorite impacts relevant to this time period as a point of reference since many of the explanations for mass extinctions throughout Earth’s history include meteorite impact(s) as a possible cause. The meteorite impact information below was obtained from the ‘Earth Impact Database’ maintained by the Planetary and Space Science Centre, University of New Brunswick, Fredericton, New Brunswick, Canada ( www.passc.net/EarthImpactDatabase).