Woolly Mammoths - Mammuthus Primigenius
A mammoth is any of a number of an extinct genus of elephant, often with long curved tusks and, in northern species, a covering of long hair. Mammoths lived during the Pleistocene epoch from 1.6 million to about 10,000 years ago. The word mammoth comes from the Russian mamont.
Mammoth remains have been found in Europe, Africa, Asia, and North America. They are believed to have originally evolved in North Africa about 4.8 million years ago, where bones of Mammuthus africanavus have been found in Chad, Libya, Morocco and Tunisia.
Despite their African ancestry, they are in fact more closely related to the modern Asian Elephant than either of the two African elephants. The common ancestor of both mammoths and Asian elephants split from the line of African elephants about 6 - 7.3 million years ago. The Asian elephants and mammoths diverged about half a million years later (5.5 - 6.3 million years ago).
In due course the African mammoth migrated north to Europe and gave rise to a new species, the southern mammoth (Mammuthus meridionalis). This eventually spread across Europe and Asia and crossed the now-submerged Bering Land Bridge into North America.
Around 700,000 years ago, the warm climate of the time deteriorated markedly and the savannah plains of Europe, Asia and North America gave way to colder and less fertile steppes.
The southern mammoth consequently declined, being replaced across most of its territory by the cold-adapted steppe mammoth (Mammuthus trogontherii).
This in turn gave rise to the woolly mammoth, Mammuthus primigenius) around 300,000 years ago. Woolly mammoths were better able to cope with the extreme cold of the Ice Ages.
The woollies were a spectacularly successful species; they ranged from Spain to North America and are thought to have existed in huge numbers. The Russian researcher Sergei Zimov estimates that during the last Ice Age, parts of Siberia may have had an average population density of sixty animals per hundred square kilometres - equivalent to African elephants today.
Most mammoths died out at the end of the last Ice Age. A definitive explanation for their mass extinction is yet to be agreed upon. However, the dwarf mammoths of Wrangel Island became extinct only around 1700 to 1500 BC.
Whether the general mammoth population died out for climatic reasons or due to overhunting by humans is controversial. Another theory suggests that mammoths may have fallen victim to an infectious disease.
New data derived from studies done on living elephants and reported by the American Institute of Biological Sciences suggests that though human hunting may not have been the primary cause toward the mammoth's final extinction, human hunting was likely a strong contributing factor.
Homo erectus is known to have consumed wooly mammoth meat as early as 1.8 million years ago.
However, the American Institute of Biological Sciences also notes that bones of dead elephants, left on the ground and subsequently trampled by other elephants, tend to bear marks resembling butchery marks, which have previously been misinterpreted as such by archaeologists.
The survival of the dwarf mammoths on Russia's Wrangel Island was due to the fact that the island was very remote, and uninhabited in the early post-Pleistocene period.
The actual island was not discovered by modern civilization until the 1820s by American whalers. A similar dwarfing occurred with Mammoths on the outer Channel Islands of California, but at an earlier period. Those animals were very likely killed by early Paleo-Native Americans.
Mammoths and Cryptozoology
There have been occasional claims that the mammoth is not actually extinct, and that small isolated herds might survive in the vast and sparsely inhabited tundra of the northern hemisphere.
In the late 19th century, there were according to Bengt Sjögren (1962) persistent rumours about surviving mammoths hiding in Alaska.
In October 1899, a man named Henry Tukeman said to have killed a mammoth in Alaska, and donated the specimen to the Smithsonian Institution in Washington. But the museum in question denied the existence of any woolly mammoth corpse, and it turned out to be a hoax.
Sjogren (1962) believes the myth got started when the American biologist C.H. Townsend traveled in Alaska, saw Eskimos trading mammoth tusks, asked if there still were living woolly mammoths in Alaska and provided them with a drawing of the animal.
In the 19th century, several reports of "large shaggy beasts" were passed on to the Russian authorities by Siberian tribesman, but no scientific proof ever surfaced.
A French charge d´affaires working in Vladivostok, M. Gallon, claimed in 1946 that in 1920 he met a Russian fur-trapper that claimed to have seen living giant, furry "elephants" deep into the taiga.
Gallon added that the fur-trapper didn't even know about mammoths before, and that he talked about the mammoths as a forest-animal at a time when they were seen as living on the tundra and snow (Sjogren, 1962). There was an alleged Soviet Air Force sighting during World War II, but this was not verified by a second sighting.
It is a common misconception that mammoths were much larger than modern elephants, an error that has led to "mammoth" being used as an adjective meaning "very big". Certainly, the largest known species, the Imperial Mammoth of California, reached heights of at least 4 meters (13 feet) at the shoulder.
Mammoths would probably weigh in the region of 6-8 tons. However, most species of mammoth were only about as large as a modern Asian Elephant, and fossils of a species of dwarf mammoth have been found on Wrangel Island off the east coast of Siberia as well as the Californian channel islands (M. exilis) and some Mediterranean islands.
Mammoths had a number of adaptations to the cold, most famously the thick layer of shaggy hair, up to 50 cm (20 in) long, for which the woolly mammoth is named. They also had far smaller ears than modern elephants; the largest woolly mammoth ear found so far was only a foot (30 cm) long, compared to six feet (1.8 m) for an African elephant. They had a flap of hairy skin which covered the anus, keeping out the cold.
Their teeth were also adapted to their diet of coarse tundra grasses, with more plates and a higher crown than their southern relatives.
Their skin was no thicker than that of present-day elephants, but unlike elephants they had numerous sebaceous glands in their skin which secreted greasy fat into their hair, improving its insulating qualities.
They had a layer of fat up to 8 cm (3 in) thick under the skin which, like the blubber of whales, helped to keep them warm.
Mammoths had extremely long tusks - up to 16 feet (5 m) long - which were markedly curved, to a much greater extent than those of elephants. It is not clear whether the tusks were a specific adaptation to their environment, but it has been suggested that mammoths may have used their tusks as shovels to clear snow from the ground and reach the vegetation buried below.
Preserved remains, genetic evidence
Preserved frozen remains of woolly mammoths have been found in the northern parts of Siberia. This is a rare occurrence, essentially requiring the animal to have been buried rapidly in liquid or semi-solids such as silt, mud and icy water which then froze.
This may have occurred in a number of ways. woolly Mammoths may have been trapped in bogs or quicksands and either died of starvation or exposure, or drowning if they sank under the surface. They may have fallen through frozen ice into small ponds or potholes, entombing them. Many are certainly known to have been killed in rivers, perhaps through being swept away by river floods; in one location, by the Berelekh River in Yakutia in Siberia, more than 9,000 bones from at least 156 individual mammoths have been found in a single spot, apparently having been swept there by the current.
To date, thirty-nine preserved bodies have been found, but only four of them are complete. In most cases the flesh shows signs of decay before its freezing and later desiccation. Stories abound about frozen mammoth corpses that were still edible once defrosted, but the original sources (e.g. William R. Farrand's article in Science 133 [March 17, 1961]:729-735) indicate that the corpses were in fact terribly decayed, and the stench so unbearable that only the dogs accompanying the finders showed any interest in the flesh.
In addition to frozen corpses, large amounts of mammoth ivory have been found in Siberia. Mammoth tusks have been articles of trade for at least 2,000 years. They have been and are still a highly prized commodity.
Guyuk, the 13th century Khan of the Mongols, is reputed to have sat on a throne made from mammoth ivory, and even today it is in great demand as a replacement for the now-banned export of elephant ivory.
Since there is a known case in which an Indian elephant and an African elephant have produced a live (though sickly) offspring, it has been theorised that if mammoths were still alive today, they would be able to interbreed with Indian elephants.
This has led to the idea that perhaps a mammoth-like beast could be recreated by taking genetic material from a frozen mammoth and combining it with that from a modern Indian elephant. Scientists hope to retrieve the preserved reproductive organs of a frozen mammoth and revive its sperm cells. However, not enough genetic material has been found in frozen mammoths for this to be attempted.
The complete mitochondrial genome sequence of Mammuthus primagenius has been determined, however (J. Krause et al, Nature 439,724-727, 9 Feb 2006). The analysis demonstrates that the divergence of mammoth, African elephant, and Asian elephant occurred over a short time, and confirmed that the woolly mammoth was more closely related to the Asian than to the African elephant.
As an important landmark in this direction, in December 2005, a team of German, UK & American researchers were able to assemble a complete mitochondrial DNA of the mammoth, which allowed them to trace the close evolutionary relationship between mammoths and the Asian elephant. African elephants branched away from the woolly mammoth around 6 million years ago, a moment in time intriguingly close to that of the similar split between gorillas, chimps and humans.
Origins of the name
The name "mammoth" comes via Russian from the Tatar language. It may have its origins in the Tatar word mamma, "earth", alluding to the long-held belief that mammoths lived underground and made burrows. The 17th century traveler Eberhard Ysbrant Ides recorded that the Evenk, Yakut and Ostyak peoples of Siberia believed that the mammoths "continually, or at least by reason of the very hard frosts, mostly live under ground, where they go backwards and forwards." Exposure to the air was enough to kill them, explaining why they were never seen alive.
Mastodons or Mastodonts (meaning "nipple-teeth") are members of the extinct genus Mammut of the order Proboscidea and form the family Mammutidae; they resembled, but were distinct from, the woolly mammoth which belongs to the family Elephantidae. Mastodons were browsers and mammoths were grazers.?
The American mastodon (Mammut americanum) lived in North America. Mastodons are thought to have first appeared almost four million years ago and became extinct about 10,000 years ago, at the same time as most other Pleistocene megafauna. Though their habitat spanned a large territory, mastodons were most common in the Ice age spruce forests of the eastern United States, as well as in warmer lowland environments. Their remains have been found as far as 300 kilometers offshore in the northeastern United States, in areas that were dry land during the low sea level stand of the last ice age. There have been, however, findings of mastodon fossils in South America and also on the Olympic Peninsula of Washington state. Mastodon fossils have been found in Stewiack, Nova Scotia, Canada, and also were discovered north of Fort Wayne, Indiana, resulting in the "Mastodons" being chosen as the mascot for athletic teams at Indiana-Purdue University at Fort Wayne (IPFW) by the students. The uncovered fossils are displayed inside Kettler Hall on the IPFW campus.
While mastodons were furry like woolly mammoths, and similar in height at roughly three meters at the shoulder, the resemblance was superficial. They differed from mammoths primarily in the blunt, conical shape of their teeth , which were more suited to chewing leaves than the high-crowned teeth mammoths used for grazing; the name mastodon (or mastodont) means mastoid teeth, and is also an obsolete name for their genus. Their skulls were larger and flatter than those of mammoths, while their skeleton was stockier and more robust.
Mastodons also seem to have lacked the undercoat characteristic of mammoths. The tusks of the mastodon sometimes exceeded five meters in length, and were nearly horizontal, in contrast with the more curved woolly mammoth tusks. Young males had vestigial lower tusks that were lost in adulthood. The tusks were probably used to break branches and twigs although some evidence suggests males may have used them in mating challenges; one tusk is often shorter than the other, suggesting that, like humans, mastodons may have had laterality.
Examination of fossilized tusks revealed a series of regularly spaced shallow pits on the underside of the tusks. Microscopic examination showed damage to the dentin under the pits. It is theorized that the damage was caused when the males were fighting over mating rights. The curved shape of the tusks would have forced them downward with each blow, causing damage to the newly forming ivory at the base of the tusk. The regularity of the damage in the growth patterns of the tusks indicates that this was an annual occurrence, probably occurring during the spring and early summer.
The meat of mastodons was a food source for early humans. Archaeologists are still trying to determine what role, if any, the early human settlers of North America played in the extinction of the mastodon. Recent studies by scientists in Ohio and New York concluded that tuberculosis may have been partly responsible for the extinction of the woolly mammoths Mastodon 10,000 years ago.
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