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A mammoth is any species of the extinct elephantidae genus Mammuthus. They lived from the late Miocene epoch (from around 6.2 million years ago) into the Holocene until about 4,000 years ago, with mammoth species at various times inhabiting Africa, Asia, Europe, and North America. Mammoths are distinguished from living elephants by their (typically large) spirally twisted tusks and in some later species, the development of numerous adaptions to living in cold environments, including a thick layer of fur.
Mammoths and are more closely related to each other than they are to . The oldest mammoth representative, Mammuthus subplanifrons, appeared around 6 million years ago during the late Miocene in what is now southern and Eastern Africa. Later in the Pliocene, by about three million years ago, mammoths dispersed into Eurasia, eventually covering most of Eurasia before migrating into North America around 1.5–1.3 million years ago, becoming ancestral to the Columbian mammoth ( M. columbi). The woolly mammoth ( M. primigenius) evolved about 700–400,000 years ago in Siberia, with some surviving on Russia's Wrangel Island in the Arctic Ocean until as recently as 4,000 years ago, still extant during the existence of the earliest civilisations in ancient Egypt and Mesopotamia.
The word mammoth was first used in Europe during the early 17th century, when referring to maimanto tusks discovered in Siberia, (2025). 9780520261600, Frances Lincoln. ISBN 9780520261600 as recorded in the 1618 edition of the Dictionariolum Russico-Anglicum. " Mammoth" Oxford English Dictionary 2000 The earliest scientific research paper on mammoths was by Vasily Tatishchev in 1725. John Bell, who was on the Ob River in 1722, said that mammoth tusks were well known in the area. They were called "mammon's horn" and were often found in washed-out river banks. Bell bought one and presented it to Hans Sloan who pronounced it an elephant's tooth.John Bell, Travels from St Petersburg in Russia to diverse parts of Asia, Edinburgh, 1806, pages 383-386
In the American colonies around 1725, enslaved Africans digging in the vicinity of the Stono River in South Carolina unearthed molar teeth recognised in modern times to belong to Columbian mammoths, with the remains subsequently examined by the British naturalist Mark Catesby, who visited the site, and later published an account of his visit in 1743. While the slave owners were puzzled by the objects and suggested that they originated from the great flood described in the Bible, Catesby noted that the slaves unanimously agreed that the objects were the teeth of elephants similar to those from their African homeland, to which Catesby concurred, marking the first technical identification of any fossil animal in North America.
In 1796, French people biologist Georges Cuvier was the first to identify woolly mammoth remains not as modern elephants transported to the Arctic, but as an entirely new species. He argued this species had gone Extinction and no longer existed, a concept that was not widely accepted at the time. Following Cuvier's identification, German naturalist Johann Friedrich Blumenbach gave the woolly mammoth its scientific name, Elephas primigenius, in 1799, placing it in the Elephas, the genus which today contains the Asian elephant ( Elephas maximus). Originally the African elephants, as well as the American mastodon (described in 1792) were also placed in Elephas. Cuvier coined the synonym Elephas mammonteus for the woolly mammoth a few months later, but E. primigenius became the widely used name for the species, including by Cuvier. The genus name Mammuthus was coined by British anatomist Joshua Brookes in 1828, as part of a survey of his museum collection.BROOKES, J., 1828. A catalogue of the anatomical and zoological museum of Jeshua Brookes, Esq., F.R.S. etc. Part 1. R.Taylor, London. 76 pp.
Thomas Jefferson, who famously had a keen interest in paleontology, is partially responsible for transforming the word mammoth from a noun describing the prehistoric elephant to an adjective describing anything of surprisingly large size. The first recorded use of the word as an adjective was in a description of a large wheel of cheese (the "Cheshire Mammoth Cheese") given to Jefferson in 1802.Simpson, J. (2009). " Word Stories: Mammoth ." Oxford English Dictionary Online, Oxford University Press. Accessed 05-JUN-2009.
Following the publication of the woolly mammoths mitochondrial genome sequence in 1997, it has since become widely accepted that mammoths and Asian elephants share a closer relationship with each other than either do to African elephant.
The following cladogram shows the placement of the genus Mammuthus among other proboscideans, based on hyoid characteristics and genetics:
It is possible to reconstruct the evolutionary history of the genus through morphological studies. Mammoth species can be identified from the number of enamel ridges/lamellae on their molars; the primitive species had few ridges, which increased gradually as new species evolved and replaced the former ones. At the same time, the crowns of the teeth became longer, and the skulls became higher from top to bottom and shorter from the back to the front over time to accommodate this.
The earliest mammoths, assigned to the species Mammuthus subplanifrons, are known from southern and eastern Africa, with the earliest records dating to the Late Miocene, around 6.2–5.3 million years ago. By the Late Pliocene, mammoths had become confined to the northern portions of the African continent with remains from this time assigned to Mammuthus africanavus. During the Late Pliocene, by 3.2 million years ago, mammoths dispersed into Eurasia via the Sinai Peninsula. The earliest mammoths in Eurasia are assigned to the species Mammuthus rumanus. The youngest remains of mammoths in Africa are from Aïn Boucherit, Algeria dating to the Early Pleistocene, around 2.3–2 million years ago (with a possible later record from Aïn Hanech, Algeria, dating to 1.95–1.78 million years ago).
Mammuthus rumanus is thought to be the ancestor of Mammuthus meridionalis, which first appeared at the beginning of the Pleistocene, around 2.6 million years ago. Mammuthus meridionalis subsequently gave rise to Mammuthus trogontherii (the steppe mammoth) in Eastern Asia around 1.7 million years ago. Around 1.5–1.3 million years ago, M. trogontherii crossed the Bering Land Bridge into North America, becoming ancestral to Mammuthus columbi (the Columbian mammoth). At the end of the Early Pleistocene Mammuthus trogontherii migrated into Europe, replacing M. meridionalis around 1–0.8 million years ago. Mammuthus primigenius (the woolly mammoth) had evolved from M. trogontherii in Siberia by around 600,000–500,000 years ago, replacing M. trogontherii in Europe by around 200,000 years ago, and migrated into North America during the Late Pleistocene.
Several dwarf mammoth species, with small body sizes, evolved on islands as a result of insular dwarfism. These include Mammuthus lamarmorai on Sardinia (late Middle-Late Pleistocene), Mammuthus exilis on the Channel Islands of California (Late Pleistocene), and Mammuthus creticus on Crete (Early Pleistocene).
The number of lamellae (ridge-like structures) on the molars, particularly on the third molars, substantially increased over the course of mammoth evolution. The earliest Eurasian species M. rumanus have around 8-10 lamellae on the third molars, while Late Pleistocene woolly mammoths have 20-28 lamellae on the third molars. These changes also corresponded with reduced enamel thickness and increasing tooth height (). These changes are thought to be adaptations to increasing abrasion resulting from the shift in the diet of mammoths from a browsing based diet in M. rumanus, towards a grazing diet in later species.
Both sexes bore tusks. A first, small set appeared at about the age of six months, and these were replaced at about 18 months by the permanent set. Growth of the permanent set was at a rate of about per year. The tusks display a strong spiral twisting. Mammoth tusks are among the largest known among proboscideans with some specimens over in length and likely in weight with some historical reports suggesting tusks of Columbian mammoths could reach lengths of around substantially surpassing the largest known modern elephant tusks.
The heads of mammoths were prominently domed. The first several thoracic vertebrae of mammoths typically had long neural spines. The back was typically sloping, with the body being wider than that of African elephants. The tails of mammoths were relatively short compared to living elephants. early mammoth species like M. meridionalis were probably relatively hairless, similar to modern elephants, M. primigenius and likely M. trogontherii had a substantial coat of fur, among other physiological adaptations for living in cold environments. Genetic sequencing of M. trogontherii-like mammoths, over 1 million years old from Siberia suggests that they had already developed many of the genetic changes found in woolly mammoths responsible for tolerance of cold conditions. Scientists discovered and studied the remains of a mammoth calf, and found that fat greatly influenced its form, and enabled it to store large amounts of nutrients necessary for survival in temperatures as low as . The fat also allowed the mammoths to increase their muscle mass, allowing the mammoths to fight against enemies and live longer. Woolly mammoths evolved a suite of adaptations for arctic life, including morphological traits such as small ears and tails to minimize heat loss, a thick layer of subcutaneous fat, and numerous sebaceous glands for insulation, as well as a large brown-fat hump like deposit behind the neck that may have functioned as a heat source and fat reservoir during winter.
The earliest mammoth species like M. subplanifrons and M. rumanus were mixed feeders (both browsing and grazing) to browsers. Throughout mammoth evolution in Eurasia, their diet shifted towards mixed feeding-grazing in M. trogontherii, culminating in the woolly mammoth, which was largely a grazer, with stomach contents of woolly mammoths suggesting that they largely fed on grass and . M. columbi is thought to have been a mixed feeder.
Like living elephants, mammoth adults may have been largely invulnerable to non-human predation, though evidence has been found for the hunting of mammoth calves by predators, such as by the Homotherium ( Homotherium).
In living proboscideans, broken tusks sometimes occur during, for example, fights between males or when elephants of both sexes shove each other to reach critical resources such as water. The fracture surface of the remaining (rooted) tooth then becomes smoothed from use. It is very likely that this also occurred in extinct proboscideans such as mammoths as seen from a tusk found at Fenstanton Gravels (Cambs, UK) which still had some of the outer layers of cementum preserved and had a smooth, polished surface on an old, fractured surface ('faceting').
The last reliable dates of the Columbian mammoth date to around 12,500 years ago. Columbian mammoths became extinct as part of the end-Pleistocene extinction event where most large mammals across the Americas became extinct approximately simultaneously at the end of the Late Pleistocene. Hunting of Columbian mammoths by Paleoindians may have been a contributory factor in their extinction. The timing of the extinction of the dwarf Sardinian mammoth Mammuthus lamarmorai is difficult to constrain precisely, though the youngest specimen likely dates to sometime around 57–29,000 years ago. The youngest records of the pygmy mammoth ( Mammuthus exillis) date to around 13,000 years ago, coinciding with the reducing of the area of the Californian Channel Islands as a result of rising sea level, the earliest known humans in the Channel Islands, and climatic change resulting in the decline of the previously dominant conifer forest ecosystems and expansion of scrub and grassland.
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