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Megatherium
Fossil range: Late Pliocene to Early Holocene
Illustration of Megatherium.
Illustration of Megatherium. The Pliocene epoch (spelled Pleiocene in some older texts is the period in the Geologic timescale that extends The Holocene is a Geological epoch which began approximately 10000 years ago (about 8000 BC
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Mammalia
Superorder:Xenarthra
Order:Pilosa
Family:Megatheriidae
Genus:Megatherium
Cuvier, 1796
Type species
Megatherium americanum Cuvier, G., 1796
Species
  • M. Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The superorder Xenarthra is a group of Placental mammals (infraclass Eutheria extant today only in the Americas The order Pilosa is a group of placental Mammals extant today only in the Americas Ground sloths are a diverse group of Extinct Sloths Mammals in the edentate Superorder Xenarthra. Baron Georges Léopold Chrétien Frédéric Dagobert Cuvier ( August 23 1769 &ndash May 13, 1832) was a French naturalist In biology a type is that which fixes a name to a Taxon. Depending on the nomenclature code which is applied to the organism in question a type may be a specimen Baron Georges Léopold Chrétien Frédéric Dagobert Cuvier ( August 23 1769 &ndash May 13, 1832) was a French naturalist altiplanicum Saint-André & de Iuliis, 2001
  • M. tarijense Gervais & Ameghino, 1880
  • M. medinae Philippi, 1893
  • M. istilarti Kraglievich, 1925
  • M. parodii Hoffstetter, 1949
  • M. sundti Philippi, 1893
  • M. gallardoi Ameghino & Kraglievich, 1921

Megatherium ("Great Beast") was a genus of elephant-sized ground sloths that lived from 2 million to 8,000 years ago. A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic Elephants ( family: Elephantidae) are large land Mammals of the order Proboscidea. Ground sloths are a diverse group of Extinct Sloths Mammals in the edentate Superorder Xenarthra. A related genus was Nothrotheriops, which were primarily bear-sized ground sloths. Nothrotheriops is a genus of Pleistocene Ground sloth found in North and South America. The rhinoceros-sized Promegatherium is suggested to be the ancestor of Megatherium. Promegatherium ("Before Megatherium " is an Genus of prehistoric Xenarthrans that lived in South America, primarily

Contents

Characteristics

Skeleton of Megatherium americanum.
Skeleton of Megatherium americanum.

Unlike its living relative, the tree sloth, Megatherium was one of the largest mammals to walk the Earth, weighing 5 tons, about as much as an African bull elephant. The living sloths comprise six Species of medium-sized Mammals that live in Central and South America belonging to the families Although mainly a quadruped (walked on four legs), its footprints show that it was capable of assuming a bipedal stance. When it stood on its hind legs, it was about twice the height of an elephant, or about twenty feet tall. This sloth, like a modern anteater, had to walk on the sides of its feet because huge claws prevented it from putting them flat on the ground. Anteaters are the four Mammal species of the suborder Vermilingua commonly known for eating Ants and Termites Together with the Sloths The Megatherium species was a member of the abundant Pleistocene megafauna - a wide variety of very large mammals that lived during the Pleistocene epoch. Pleistocene megafauna is the set of Species of large animals &mdash Mammals Birds and Reptiles &mdash that lived on Earth during the Pleistocene

Megatherium had a robust skeleton with a large pelvic girdle and a broad muscular tail. Its large size and specially adapted body made it possible to feed at heights otherwise unreachable by other contemporary herbivores. Herbivory is a form of Predation in which an Organism, known as a herbivore, consumes principally Autotrophs ref name=Campbell>Campbell Rising on its powerful hind legs and using its tail to form a tripod, Megatherium was able to support its massive body weight while using the curved claws on its long forelegs to pull down branches with the choicest leaves. Its large deep jaw is believed to have housed a long tongue, as in the modern tree sloth, which it would then use to pull leaves into its mouth. The living sloths comprise six Species of medium-sized Mammals that live in Central and South America belonging to the families

Some recent morpho-functional analysis (Bargo, 2001) indicate that M. americanum was well adapted for strong and mainly vertical biting. The teeth are extremely hypsodont and bilophodont, and the sagittal section of each loph is triangular with a sharp edge. Hypsodont Dentition is characterized by high-crowned teeth and enamel which extends past the gum line. This suggests that the teeth were used mainly for cutting, rather than grinding, and that hard and fibrous food was not the main dietary component.

There is a common misbelief that the sabre-toothed cat Smilodon hunted Megatherium, but healthy adult sloths were far too big for even this large cat to attack. Smilodon (ˈsmаɪləˌdɒn sometimes called saber-toothed tiger, is an extinct Genus of large machairodontine Saber-toothed Richard Fariña and Ernesto Blanco of the Universidad de la República in Montevideo have analysed a fossil skeleton of M. The University of the Republic (Universidad de la República is Uruguay 's public University. Montevideo (monteβi'ðeo is the largest city the capital and chief port of Uruguay. americanum and discovered that its olecranon--the part of the elbow to which the triceps muscle attaches--was very short. The olecranon is a large thick curved eminence situated proximal end of the Ulna in the Forearm. The triceps brachii ( Latin for "three-headed" of the arm is the large muscle on the back of the human Upper limb. This adaptation is found in carnivores and optimises speed rather than strength. A carnivore (ˈkɑrnɪvɔər meaning 'meat eater' ( Latin carne meaning 'flesh' and vorare meaning 'to devour' is any animal with a diet consisting The researchers say this would have enabled M. americanum to use its claws aggressively, like daggers (Fariña and Blanco, 1996). The conclusion is that due to its nutrient-poor habitats, Megatherium may have actually taken over the kills of Smilodon. A number of adult Glyptodon fossils have also been found where the shell was turned upside down. Glyptodon (Greek for "grooved or carved tooth" was a large armored Mammal, related to the Armadillo, that lived during the Pleistocene This hints at Megatherium scavenging or hunting this animal, as no other known animal existed in South America during that period that could flip an adult Glyptodon. Glyptodon (Greek for "grooved or carved tooth" was a large armored Mammal, related to the Armadillo, that lived during the Pleistocene

Distribution

Megatherium was endemic to South America (McKenna and Bell, 1997). South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a

Habits

Illustration of Megatherium from around 1920.
Illustration of Megatherium from around 1920. Year 1920 ( MCMXX) was a Leap year starting on Thursday (link will display 1920 of the Gregorian calendar

Little is known about the giant ground sloth. It may have used its tremendous size and strength to take over the kills of Smilodon and to scavenge or hunt Glyptodon (see "Characteristics" section above) while its very thick skin, which was covered with dense, heavy fur, protected it from predators.

It was a herbivorous animal and, although it could stand on its hind legs, using its tail as a balancing tripod, to reach for vegetation, the giant ground sloth fed mainly on plants that grew on the ground.

It is believed that the giant sloth lived in groups, but it may have lived singly in caves. According to the theory of the social giant sloth, the groups consisted of two males and seven females. At any given time, up to four female sloths would be pregnant or nursing, while the remaining three tended to the hunting and gathering for the menfolk. It is also believed that it lived in a woodland and grassy environments.

Diet and feeding habits

The giant ground sloth lived in the lightly wooded areas of South America, feeding on the leaves such as yuccas, agaves, and grasses. The yuccas comprise the Genus Yucca of 40-50 species of perennials Shrubs and Trees in the Agave family Agave is a succulent Plant of a large Botanical Genus of the same name belonging to the family Agavaceae. Grass is the common word that generally describes Monocotyledonous green Plants The family Gramineae ( Poaceae) are the "true grasses" and include The closely related genus Eremotherium lived in more tropical environments further north, and in North America. Eremotherium is an extinct genus of Ground sloth. Sources Dinosaur Encyclopedia by Jayne Parsons After Pulling itself upright to sit on its haunches or to stand, the giant ground sloth balanced its weight with its tail. It then tugged at plants with is feet, digging them up with the five sharp claws on each foot. The sloth used its simple teeth to grind down food before swallowing it, and its highly developed cheek muscles helped in this process. The sloth's stomach was able to digest coarse and fibrous food. For millions of years, the sloth had no enemies to bother it, so it was probably a diurnal feeder. It is likely that it spent a lot of time resting to aid digestion.

Evolution

The ground sloths, as with all other xenarthrans, evolved in isolation in South America, while it was an island during the Paleogene. The superorder Xenarthra is a group of Placental mammals (infraclass Eutheria extant today only in the Americas The Paleogene (alternatively Palaeogene) is a geologic period and system that began 65 During the Pliocene, the Central American Isthmus formed, causing the Great American Interchange, and a mass extinction of much of the indigenous South American megafauna. The Pliocene epoch (spelled Pleiocene in some older texts is the period in the Geologic timescale that extends The Great American Interchange was an important paleozoogeographic event in which land and freshwater fauna migrated from North America via Central Ground sloths were largely unaffected and continued to thrive in spite of competition from the northern immigrants. In fact, ground sloths were among the various South American animal groups to migrate northwards, into North America, where they remained and flourished until the late Pleistocene. In the south, the giant ground sloth flourished until about 10,000 years ago. Some cite the appearance of human hunters as the cause of its extinction, others climatic changes; however, the actual cause is unknown.

The oldest (and smallest) species of Megatherium is M. altiplanicum of Pliocene Bolivia. The Republic of Bolivia (República de Bolivia) named after Simón Bolívar, is a Landlocked country in central South America. It was very similar to the Miocene ground sloth, Promegatherium, and was about the size of a rhinoceros. The Miocene is a geological epoch of the Neogene period and extends from about 23 Species of Megatherium became larger and larger, with the largest species, M. americanum of the late Pleistocene, reaching the size of an African Elephant. African elephants are the species of Elephants in the Genus Loxodonta, one of the two existing genera in Elephantidae.

When the ancestors of the giant ground sloth became established in South America, the land bridge joining North and South America was submerged. The sloth and other edentates (simple toothed creatures) developed undisturbed and were unique to this part of the world. The edentate families looked very different but had certain things in common: Simple teeth and different numbers of vertebrae to provide varying degrees of spinal movement. Nearly six million years passed before the land dividing the continents appeared again. Some sloths and other edentates then moved further north and became widespread before they disappeared completely. In the south the giant ground sloth flourished until about 10,000 years ago. Some cite the appearance of human hunters as the cause of its extinction, others climatic changes, however the actual cause is unknown.

Megatherium In Popular Culture

Gallery

Megatherium americanum

See also

Megatherium Club

References


External links


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