After going through four eons, six eras, and fourteen periods we finally reached our current period. The Quaternary period is the shortest on the Geological Time Scale and it is still ongoing. We divide it into Pleistocene and Holocene (from 11.7 thousand years ago)
All the articles of History of Life series
Animals of the Early Quaternary
Animals were quite modern at the beginning of the period. However, there is one major difference, comparing to today’s situation. The Pleistocene had many more large land mammals. Those include extinct species we know from museums and pop culture like Mammoths and Mastodonts. Moreover, still existing species, like tigers, lions, and bears, were also bigger than today. The Pleistocene is also the time when most of the modern human development took place. In the beginning, there were still hominins, modern humans appeared about two hundred thousand years ago. They appeared in Africa and migrated all over the globe during and after the Ice Age.
Image Courtesy: Museum of Natural History, Yale University
The Pleistocene Epoch- The Ice Age
The new period did not give a warm welcome. The cooling trend from the Neogene continued and the series of glaciations began. It was not much compared to the Proterozoic Ice Age- at the peak, 30% of the planet was covered with ice. The freeze spread hundreds of kilometers further into continents. At the edges, average global temperatures reached -6 and 0 degrees Celsius. Due to the glaciation, sea levels dropped over 100 m. There were huge lifeless areas of the continents, huge land mammals went extinct probably due to lack of resources. That began the current extinction event, which is ongoing. The end of the epoch is marked with the end of both the Last Glacial Period and the archaeological Paleolithic age.
Image Courtesy
The Holocene Epoch
Compared to all other periods and epochs, Holocene is exceptionally short. It started about 11.7 thousand years ago and as the last geological epoch, is still ongoing. We can definitely say it is marked with the domination of humans. From the first Neolithic revolutionary cultures, through great ancient civilization, and moonlanding, up until today. The Quaternary extinction event is sometimes called the sixth extinction event. We describe it as a series of human-caused extinctions, however, some parts happened also due to other factors. The life development in that short period of time is barely observable, however, the specific microclimates led to some adaptations. The climate was stable through most of the period and the climate changes were usually local.
Changes in Earth During the Quaternary Period
Despite the Ice Age, we can call the Quaternary period quite stable. Most climate changes are local, however, due to human activity, we are facing anomalies globally. The continents drifted to today’s position quite soon: at the beginning of the Pleistocene, the plate tectonics were no further than 100 km from their current positions. The islands formed due to the interactions between them. The level of glaciation and permafrost established nearby the Poles and in the mountains. The borders between climate zones established. We need to remember, that reaching the present doesn’t mean the Earth stopped changing. Plate tectonics always move a little and in millions of years, they will probably look completely different than today.
Image Courtesy
The Quaternary Period Evidence
We will all be evidence of the Quaternary period someday, however, let’s discuss the already existing pieces. There are fossils of megafauna, including saber-toothed cats, mammoths, and many pre-human hominins. The evidence of glaciation includes frozen pieces found in the regions of permafrost. Additionally, following the modern shape of the Earth’s surface, we can learn a lot about its past. For example, the ribbon lakes show the reach of ‘migration’ of late Pleistocene glaciers. Due to the separation of continents, some species survived on one continent and went extinct on the other. For example, camels first developed in today’s South Dacota, US, however, they went extinct in the Pliocene there, but two species survived in Asia and Africa.
Image Courtesy
Read the previous in the series: The Neogene Period.
Author’s message
I hope that the article helped you learn about the Quaternary period. If you enjoyed it, please share it with family and friends. In the last article, we will discuss the evolution of humans and therefore conclude the series. Until then, feel free to email me or use a contact form below.
Pretty nice post. I just stumbled upon your blog and wanted to say
that I have truly enjoyed surfing around your blog posts.
In any case I will be subscribing to your rss feed and I hope you write again soon!
[…] In the previous article, we discussed the last period in Earth’s history. Now it is time we talk about the evolution of humankind and conclude the History of Life series. […]