The genus Mammuthus shares a number of characteristics with living elephant genera, Elephas and Loxodonta, and are included in the family Elephantidae. They possessed a similar dentition to extant elephant species, with all canines and incisors lost save for two incisors that developed into tusks in the upper jaw. Only one pair of molar teeth were to be found as functional grinding surfaces in each jaw. Like modern elephant species, the mammoths are thought to have been grazers.
The famous Woolly Mammoth was a single species belonging to the genus Mammuthus, which it shared with a diversity of other species. The oldest recorded specimens of the genus have been found in Ethiopia and South Africa Mammuthus africanavus , dating from the early Miocene. These early mammoths are probably closely related to the common ancestor of mammoths and Elephas, the genus including the extant Asiatic Elephant. Mammoth remains have been found in Africa and Eastern Asia, but the majority of mammoth diversity is found in Europe, North America and the Middle East.
Woolly Mammoth tusks have been found in Siberia since before they were identified as belonging to a Proboscidean. When remains of Woolly Mammoths were first described scientifically they were initially mistaken for members of the genus Elephas. It was recognized as a distinct genera by Johann Blumenbach in 1799. It is known from fossils and other remains of Late Pleistocene age from high latitudes throughout the Northern Hemisphere. Analysis of mitochondrial DNA from the hair of Woolly Mammoths indicates they were split in to two temporally distinct groups, and may be considered separate subspecies.
The Woolly Mammoth bore a number of physical adaptations to cope with the cold climate of the Late Pleistocene glaciations, including a thick coat of hair and layers of lipid-rich tissue to improve insulation, and small ears and tail to reduce surface area. DNA analysis has recognised a number of specific differences in the haemoglobin protein in mammoth red blood cells and those of living elephants that are thought to be adaptations to low temperatures. The Woolly Mammoth existed within the most recent glacial event of the Pleistocene. More ancient species of Mammoth were adapted to the cold climates associated with earlier glacial events. The Steppe Mammoth, Mammuthus trogontherii, known from the middle Pleistocene of Europe and Asia, was a considerably larger Mammoth species that may be ancestral to the Woolly Mammoth. One of the largest elephantid skeletons ever found belongs to the Steppe Mammoth, found in West Runton in Norfolk, England. Nicknamed the West Runton Elephant, this specimen is the oldest elephantid remains found in the United Kingdom.
Mammuthus included a number of small species thought to be examples of insular dwarfism, where species reduce body size to cope with limited resources on islands.
The Pygmy Mammoth, Mammuthus exilis, was a relatively small Mammoth found on the North Channel Islands of the coast of California, USA, that is thought to have reached no more than approximately two meters at the shoulder.
The Dwarf Mammoth, Mammuthus lamarmorae, known from fossils from the Late Pliocene to the Late Pleistocene of Sardinia, is the smallest known mammoth species. The remains are scant and size is difficult to estimate, though a shoulder height of less than 1.5 meters has been proposed. DNA analysis has hinted that dwarf elephantids on the island of Crete may also be Mammoths, rather than their current designated genera, Elephas.
A population of Woolly Mammoths greatly reduced in size are known to have lived on the island of Wrangel, which lies within the Arctic Circle off the coast of Northern Russia. Carbon isotope dating indicates that these Woolly Mammoths died out 1650 years BC, the most recent date attributed to the extinction of any Mammoth population.
Mammoths appear to have had a strong cultural relationship with humans, being depicted in cave paintings and handcrafted artifacts. Mammoth bones bearing cut marks have been found, some of them associated with spear points, indicating that Mammoths were used as a food source for humans. Evidence for hunting found in association with Mammoth remains have been attributed to both our own species, Homo sapiens, and the extinct contemporary species Homo neanderthalensis. Mammoth remains have been found in association with spear points characteristic of those manufactured by the Clovis paleoindians of North America. Long after the Mammoths' extinction, Mammoth tusks are still prized for their ivory and continue to be traded in parts of Siberia where they can be found.
Numerous specimens of Woolly Mammoth have been documented that have included soft tissues preserved by the cold, often in permafrost or frozen mud. Rumors of Mammoths so well preserved that their flesh was still palatable can be dismissed, most specimens having undergone partial decomposition before preservation. However, soft tissue preservation has informed greatly of Woolly Mammoth anatomy, which arguably is now better understood than any other prehistoric taxa.
The most complete Mammoth carcass known belongs to a female found in 2007, nicknamed 'Lyuba', estimated to have been two to three months old at the time of death. Some hair, the majority of soft tissues and stomach contents are preserved, however the tail, one ear and some toenails are missing. Lyuba appears to have been a healthy individual with a well-developed layer of subcutaneous fat. Sediment found within Lyuba's intestines and a partially collapsed forehead indicates that she drowned in a muddy pool. If the complex social relationships of living elephants can be used as a proxy for social relationships in Mammoths, this must have been a deeply distressing experience for Lyuba's mother and the rest of the herd.
The recovery of soft tissues and cell components from frozen Woolly Mammoth carcasses has generated speculation on the possibility of re-creating the species artificially. While theoretically feasible, attempts to breed or clone Mammoths are beset with numerous practical problems. Hybridization of Mammoths with elephants and then using artificial selection to purify the lineage has been proposed as one method, but attempts to recover viable Mammoth sperm from frozen carcasses have ended in failure. The Mammoth genome has yet to be recovered entire from any soft tissue specimen. The total length of the Mammoth genome and the number of chromosomes found within Mammoth nuclei is not known, but attempts to sequence the Mammoth genome from preserved DNA fragments continue. Mammoth mitochondrial DNA has now successfully been sequenced from bone samples.
A Russian project to restore a Pleistocene-age ecosystem to an area of the Yakutia region in Siberia has been proposed as a possible home for cloned Woolly Mammoths, should they be created successfully. Dubbed 'Pleistocene Park' by its creators, a rather uninspiring reference to Michael Chrichton's Jurassic Park, if completed it will host a number of mammal species that would have coexisted with Mammoths during the Pleistocene, such as reindeer and musk oxen.