Megatherium
Megatherium | |
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M. americanum skeleton, Natural History Museum, London | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Pilosa |
Clade: | † Megatheria
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Family: | †Megatheriidae |
Subfamily: | †Megatheriinae |
Genus: | †Megatherium Cuvier, 1796 |
Type species | |
†Megatherium americanum Cuvier, 1796
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Subgenera
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Megatherium
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Map showing the distribution of all Megatherium species in red, inferred from fossil finds | |
Synonyms | |
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Megatherium (/mɛɡəˈθɪəriəm/ meg-ə-THEER-ee-əm; from Greek méga (μέγα) 'great' + theríon (θηρίον) 'beast') is an extinct genus of ground sloths endemic to South America that lived from the Early Pliocene[1] through the end of the Pleistocene.[2] It is best known for the elephant-sized type species M. americanum, sometimes known as the giant ground sloth, or the megathere, native to the Pampas through southern Bolivia during the Pleistocene. Various other smaller species belonging to the subgenus Pseudomegatherium are known from the Andes.
Megatherium is part of the sloth family
Taxonomy
Megatherium is divided into 2 subgenera, Megatherium and Pseudomegatherium. Taxonomy according to Pujos (2006) and De Iuliis et al (2009):[5][6]
- Subgenus Megatherium
- †M. altiplanicum Saint-André & de Iuliis 2001
- †M. americanum Cuvier 1796
- Subgenus Pseudomegatherium Kraglievich 1931
- †M. celendinense Pujos 2006
- †M. medinae Philippi 1893
- †M. sundti Philippi 1893
- †M. tarijense Gervais & Ameghino, 1880
- †M. urbinai Pujos & Salas 2004
The first fossil specimen of Megatherium was discovered in 1788 by Manuel Torres, on the bank of the Luján River in Argentina. The fossil was shipped to Museo Nacional de Ciencias Naturales in Madrid the following year, where it remains. It was reassembled by museum employee Juan Bautista Bru, who also drew the skeleton and some individual bones.[7]
Based on Bru's illustrations,
Fossils of Megatherium and other western megafauna proved popular with the Georgian-era public, preceding the discovery of giant dinosaurs some decades later.
Since the original discovery, numerous other fossil Megatherium skeletons have been discovered across South America, in
The species Megatherium (Pseudomegatherium) tarijense, appears to be a junior synonym of M. americanum, and merely a small individual.[12]
The species Megatherium filholi Moreno, 1888 of the Pampas, previously thought to be a junior synonym of M. americanum representing juvenile individuals, was suggested to be a distinct valid species in 2019.[13]
Megatherium gallardoi Ameghino & Kraglievich 1921 from the Ensenadan of Argentina was suggested to be a valid species in 2008, most closely related to M. americanum and M. altiplanicum.[14]
M. parodii Hoffstetter 1949, and M. istilarti Kraglievich 1925 have not had their validity assessed in recent literature.
Evolution
During the
The
The following sloth family phylogenetic tree is based on collagen and mitochondrial DNA sequence data (see Fig. 4 of Presslee et al., 2019).[15]
Folivora
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Description
Megatherium americanum was one of the largest animals in its habitat, weighing up to 3.8–4.58 t (8,400–10,100 lb),
Megatherium had a robust
One study has proposed that Megatherium was mostly hairless, like modern elephants, because its large size and small surface-area-to-volume ratio would have made it susceptible to overheating.[27]
Mouth
Megatherium had a narrow, cone-shaped mouth and
Like other sloths, Megatherium lacked the
Habitat
Megatherium inhabited
Paleobiology
The giant ground sloth lived mostly in groups, but it may have lived singly in caves. It probably had mainly a browsing diet in open habitats, but also it probably fed on other moderate to soft tough food. For millions of years, the sloth did not have many enemies to bother it, so it was probably a diurnal animal.[citation needed]
The giant ground sloth was a herbivore, feeding on leaves such as
A recent morpho-functional analysis
While it has been suggested that the giant sloth may have been partly
Extinction
The youngest unambiguous dates for Megatherium are from the end of the Late Pleistocene. Supposed early Holocene dates obtained for Megatherium and other Pampas megafauna have been questioned, with suggestions that they are likely due to
Towards the end of the Late Pleistocene, humans first arrived in the Americas, with some of the earliest evidence of humans in South America being the
Cultural references
The Megatherium Club, named for the extinct animal and founded by William Stimpson, was a group of Washington, D.C.-based scientists who were attracted to that city by the Smithsonian Institution's rapidly growing collection, from 1857 to 1866.
Notes
- ^ Martin (2005), p. 35
References
- ^ a b c Saint-André, P. A.; De Iuliis, G. (2001). "The smallest and most ancient representative of the genus Megatherium Cuvier, 1796 (Xenarthra, Tardigrada, Megatheriidae), from the Pliocene of the Bolivian Altiplano" (PDF). Geodiversitas. 23 (4): 625–645. Archived from the original (PDF) on 2013-10-29. Retrieved 14 April 2016.
- ^ .
- ^ OCLC 236490247.
- ^ PMID 30854426.
- ^ S2CID 84225654.
- S2CID 84272333.
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- ^ ISSN 1313-2970.
- ^ Bürgl, Hans (1956). "Restos de Megatherium y otros fósiles de Quipile, Cundinamarca". Ingeominas: 1–14. Retrieved 2017-05-03.
- ^ De Porta, Jaime (1961). "La posición estratigráfica de la fauna de Mamíferos del pleistoceno de la Sabana de Bogotá". Boletín de Geología, Universidad Industrial de Santander. 7: 37–54. Retrieved 2017-05-03.
- .
- ^ S2CID 84272333.
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- ISSN 1280-9659.
- ^ (PDF) from the original on 2022-10-09.
- PMID 31178321.
- OCLC 58055404. Retrieved 2014-09-11.
- S2CID 225141277.
- ISSN 0035-6883.
- ^ a b c d Bargo, M. S. (2001). "The ground sloth Megatherium americanum: Skull shape, bite forces, and diet" (PDF). Acta Palaeontologica Polonica. 46 (2): 173–192. Archived (PDF) from the original on 2022-10-09. Retrieved 2012-07-22.
- ^ Blanco, R.E; Czerwonogora, Ada (2003). "The gait of Megatherium Cuvier 1796 (Mammalia, Xenarthra, Megatheriidae)". Senckenbergiana Biologica. 83 (1): 61–68.
- ^ .
- PMID 24676170.
- ISBN 9780792269977.
- ^ BBC (2012). "Megatherium Wildfacts". BBC. Archived from the original on 2014-02-01. Retrieved 2012-07-22.
- ISBN 978-1-55407-181-4.
- ^ Fariña, R. (June 2002). "Megatherium, the hairless: appearance of the great Quaternary sloths (Mammalia;Xenarthra)". Ameghiniana. 39 (2): 241–244 – via ResearchGate.
- ^ S2CID 39664746.
- ^ PMID 3857888.
- S2CID 8106788.
- ISBN 978-0231110129.
- ^ C. Michael Hogan (2008) Cueva del Milodon, Megalithic Portal
- . Retrieved 2014-05-27.
- S2CID 9451444.
- .
- S2CID 36156087.
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- S2CID 224935851.
- ^ PMID 33846353.
- .
- ^ OCLC 1084743779.)
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