This mammoth, found in deposits in Russia, was one of the largest land
mammals of the Pleistocene, the time period that spanned from . Pleistocene biotas were extremely close to modern ones -- many
genera and even species of Pleistocene conifers, mosses, flowering
plants,
insects,
mollusks,
birds,
mammals, and others
survive to this day. Yet the Pleistocene was also characterized by the presence
of distinctive large land mammals and birds. Mammoths and their cousins the
mastodons, longhorned bison,
sabre-toothed
cats,
giant ground sloths, and many other large mammals characterized
Pleistocene habitats in North America, Asia, and Europe. Native horses and
camels galloped across the plains of North America. Great teratorn birds with
25-foot wingspans stalked prey. Around the end of the Pleistocene, all these
creatures went extinct (the horses living in North America today are all
descendants of animals brought from Europe in historic times).
It was during the Pleistocene that the most recent episodes of global warming and
cooling, took place. Much of the world's temperate zones
were alternately covered by glaciers during cool periods and uncovered during
the warmer interglacial periods when the glaciers retreated. Did this cause the
Pleistocene extinctions? It doesn't seem likely; the large mammals of the
Pleistocene weathered several severe climate shifts.
The Pleistocene also saw the evolution and expansion of our own species, Homo sapiens or modern man, from a cradle beleived to be have been situated in East Afric. By by the close of the Pleistocene ie. 10 000 years BP, modern humans had spread through most of the world, including Eurasia, Australia, and the Americas. See a
slide show on this issue.
According to a controversial theory, first proposed in the 1960s, human hunting around the close of the Pleistocene caused or contributed to the extinction of many of the Pleistocene large mammals. It is true that the extinction of large animals on different continents appears to correlate with the arrival of humans, but questions remain as to whether early human hunters were sufficiently numerous and technologically advanced to wipe out whole species. It has also been hypothesized that some disease wiped out species after species in the Pleistocene. The issue remains unsolved; perhaps the real cause of the Pleistocene extinction was a combination of these factors.
Many paleontologists study Pleistocene fossils in order to understand the
climates of the past. The Pleistocene was not only a time during which climates
and temperatures shifted dramatically; Pleistocene fossils are often abundant,
well-preserved, and can be dated very precisely. Some, such as diatoms,
foraminifera,
and
plant pollen,
are both abundant and highly informative about paleoclimates. Today, there is
concern about future climate change (e.g. global warming) and how it will affect
us. Paleontologists who work on Pleistocene fossils are providing a growing
amount of data on the effect of climate change on the Earth's biota, making it
possible to understand the effects of future climate change.