Linnaeus's two-toed sloth

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Linnaeus's two-toed sloth [1]
Cholepus didactylus - Flickr - Dick Culbert.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Pilosa
Family: Choloepodidae
Genus: Choloepus
Species:
C. didactylus
Binomial name
Choloepus didactylus
Linne's Two-toed Sloth area.png
Linnaeus's two-toed sloth range
Synonyms

Bradypus didactylusLinnaeus, 1758

Linnaeus's two-toed sloth (Choloepus didactylus), also known as the southern two-toed sloth, unau, or Linne's two-toed sloth is a species of sloth from South America, found in Venezuela, Suriname, Guyana, French Guiana, Colombia, Ecuador, Peru, and Brazil north of the Amazon River. There is now evidence suggesting the species' range expands into Bolivia. [4] It's the largest extant sloth species. [5]

Contents

Description

Males and females are the same size, growing to lengths of approximately 21” to 35” (not including the length of the tail) and weigh 9 to 24 pounds. [5] Their fur color ranges from a brownish yellow to a pale tone of brown, however, in the wild their fur sometimes has a green hue from algae that grows on their fur during the rainy season. [5] Their belly fur is slightly lighter in color than the body and they have no undercoat. [5] The belly hair is parted along the midline and flows towards the animals back (spine), the opposite direction that fur flows on most other mammals. [5] Young sloths tend to have softer and darker fur than adults. [5]

Phylogeny

Sloths belong to the order Pilosa, which also includes anteaters. They belong to the super order Xenarthra, which includes the Cingulata. Xenarthra are edentate or toothless. They lack incisors and have a large reduction in number of teeth with only four to five sets remaining including canines. [6]

Modern sloths are divided into two families based on the number of toes on their front feet, Choloepodidae and Bradypodidae. Linnaeus's two-toed sloth and Hoffmann's two-toed sloth ( Choloepus hoffmanni ) belong to the family Choloepodidae, which included extinct ground sloths. [7]

Morphology

Choloepus didactylus are larger than three-toed sloths. They have longer hair, bigger eyes, and their back and front legs are more equal in length. [8] Their ears, hind feet and head are generally larger than Bradypodidae. They do however have a shorter tail. [9] Their shoulder height, the height from the shoulder blade to the tips of the claw is longer than three-toed sloths, indicating longer arms. [9]

The species has relatively few teeth; it has four to five sets including canines and lacks incisors. Molars are indistinguishable from premolars. [5] The teeth are rootless [5] and lack enamel, consisting only of two layers ever-growing dentin. [6] Supernumerary teeth have occasionally been observed, but this has been reported in almost all mammalian orders. [6]

Ecology

C. didactylus is a solitary, nocturnal and arboreal animal, found in rainforests. The two-toed sloth falls prey to wild cats such as the ocelot and jaguar as well as large birds of prey such as the harpy and crested eagles. Predation mainly occurs when the sloth descends to the ground in order to defecate or change trees. [7] Anacondas have also been known to hunt sloths. [7] It is able to swim, making it possible to cross rivers and creeks, but maybe also making it more available to a predator like an anaconda.

Two-toed sloths live in ever-wet tropical rainforests that are hot and humid. They tend to live in areas where there is a lot of vine growth so they can easily travel from tree to tree in the canopies of the forests. [7] They mainly eat leaves, but there is lacking data on the extent of their diet due to their nocturnal lifestyle and camouflage. [7]

C. didactylus, similar to other sloth species, have a low rate of metabolism, food intake, and defecation, despite their relatively large body mass and their high volumes of methane production. They retain their digested material for long periods of time, due to a combination of their low defecation rates and large digestive systems. [10] This long digestion period appears to cause the sloths’ high volumes of methane production, more than most other, similar herbivores. [10] These high methane levels may also be the result of high formate levels in their digested material. [11]

See also

Related Research Articles

<span class="mw-page-title-main">Xenarthra</span> Superorder of mammals including anteaters, sloths, and armadillos

Xenarthra is a major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos. Extinct xenarthrans include the glyptodonts, pampatheres and ground sloths. Xenarthrans originated in South America during the late Paleocene about 60 million years ago. They evolved and diversified extensively in South America during the continent's long period of isolation in the early to mid Cenozoic Era. They spread to the Antilles by the early Miocene and, starting about 3 million years ago, spread to Central and North America as part of the Great American Interchange. Nearly all of the formerly abundant megafaunal xenarthrans became extinct at the end of the Pleistocene.

<span class="mw-page-title-main">Giant anteater</span> Species of mammal

The giant anteater is an insectivorous mammal native to Central and South America. It is one of four living species of anteaters, of which it is the largest member. The only extant member of the genus Myrmecophaga, it is classified with sloths in the order Pilosa. This species is mostly terrestrial, in contrast to other living anteaters and sloths, which are arboreal or semiarboreal. The giant anteater is 182 to 217 cm in length, with weights of 33 to 50 kg for males and 27 to 47 kg for females. It is recognizable by its elongated snout, bushy tail, long fore claws, and distinctively colored pelage.

<span class="mw-page-title-main">Mylodontidae</span> Extinct family of ground sloths

Mylodontidae is a family of extinct South American and North American ground sloths within the suborder Folivora of order Pilosa, living from around 23 million years ago (Mya) to 11,000 years ago. This family is most closely related to another family of extinct ground sloths, Scelidotheriidae, as well as to the extant arboreal two-toed sloths, family Choloepodidae; together these make up the superfamily Mylodontoidea. Phylogenetic analyses based on morphology uncovered the relationship between Mylodontidae and Scelidotheriidae; in fact, the latter was for a time considered a subfamily of mylodontids. However, molecular sequence comparisons were needed for the correct placement of Choloepodidae. These studies have been carried out using mitochondrial DNA sequences as well as with collagen amino acid sequences. The latter results indicate that Choloepodidae is closer to Mylodontidae than Scelidotheriidae is. The only other living sloth family, Bradypodidae, belongs to a different sloth radiation, Megatherioidea.

<span class="mw-page-title-main">Scelidotheriidae</span> Extinct family of prehistoric ground sloths

Scelidotheriidae is a family of extinct ground sloths within the order Pilosa, suborder Folivora and superfamily Mylodontoidea, related to the other extinct mylodontoid family, Mylodontidae, as well as to the living two-toed sloth family Choloepodidae. The only other extant family of the suborder Folivora is the distantly related Bradypodidae. Erected as the family Scelidotheriidae by Ameghino in 1889, the taxon was demoted to a subfamily of Mylodontidae by Gaudin in 1995. However, recent collagen sequence data indicates the group is less closely related to Mylodon and Lestodon than Choloepus is, and thus it has been elevated back to full family status by Presslee et al. (2019).

<span class="mw-page-title-main">Pale-throated sloth</span> Species of mammals related to anteaters and armadillos

The pale-throated sloth, occasionally known as the ai, is a species of three-toed sloth that inhabits tropical rainforests in northern South America.

<span class="mw-page-title-main">Maned sloth</span> Species of mammals related to anteaters and armadillos

The maned sloth is a three-toed sloth that is native to South America. It is one of four species of three-toed sloths belonging to the suborder Xenarthra and are placental mammals. They are endemic to the Atlantic coastal rainforest of southeastern and northeastern Brazil, located in the states of Espírito Santo, Rio de Janeiro and Bahia. Each of the individuals within the species are genetically distinct with different genetic makeup.The maned sloth is listen under Vulnerable (VU) according to the IUCN Red List and have a decreasing population trend.

<span class="mw-page-title-main">Silky anteater</span> Species of mammals related to sloths and armadillos

The silky anteater, also known as the pygmy anteater, has traditionally been considered a single species of anteater, Cyclopes didactylus, in the genus Cyclopes, the only living genus in the family Cyclopedidae. Found in southern Mexico, and Central and South America, it is the smallest of all known anteaters. It has nocturnal habits and appears to be completely arboreal; its hind feet are highly modified for climbing.

<span class="mw-page-title-main">Brown-throated sloth</span> Species of New World mammals related to anteaters and armadillos

The brown-throated sloth is a species of three-toed sloth found in the Neotropical realm of Central and South America.

<span class="mw-page-title-main">Hoffmann's two-toed sloth</span> Species of mammals related to anteaters and armadillos

The Hoffmann's two-toed sloth, also known as the northern two-toed sloth, is a species of sloth from Central and South America. It is a solitary, largely nocturnal and arboreal animal, found in mature and secondary rainforests and deciduous forests. The common name commemorates the German naturalist Karl Hoffmann.

<span class="mw-page-title-main">Pilosa</span> Order of mammals

The order Pilosa is a clade of xenarthran placental mammals, native to the Americas. It includes anteaters and sloths. The name comes from the Latin word for "hairy".

<span class="mw-page-title-main">Two-toed sloth</span> Genus of sloth

Choloepus is a genus of xenarthran mammals of Central and South America within the monotypic family Choloepodidae, consisting of two-toed sloths, sometimes also called two-fingered sloths. The two species of Choloepus, Linnaeus's two-toed sloth and Hoffmann's two-toed sloth, were formerly believed on the basis of morphological studies to be the only surviving members of the sloth family Megalonychidae, but have now been shown by molecular results to be closest to extinct ground sloths of the family Mylodontidae.

<span class="mw-page-title-main">Three-toed sloth</span> Genus of mammals

The three-toed or three-fingered sloths are arboreal neotropical mammals. They are the only members of the genus Bradypus and the family Bradypodidae. The five living species of three-toed sloths are the brown-throated sloth, the maned sloth, the pale-throated sloth, the southern maned sloth, and the pygmy three-toed sloth. In complete contrast to past morphological studies, which tended to place Bradypus as the sister group to all other folivorans, molecular studies place them nested within the sloth superfamily Megatherioidea, making them the only surviving members of that radiation.

<span class="mw-page-title-main">Sloth</span> Group of tree dwelling mammals noted for slowness

Sloths are a Neotropical group of xenarthran mammals constituting the suborder Folivora, including the extant arboreal tree sloths and extinct terrestrial ground sloths. Noted for their slowness of movement, tree sloths spend most of their lives hanging upside down in the trees of the tropical rainforests of South America and Central America. Sloths are considered to be most closely related to anteaters, together making up the xenarthran order Pilosa.

<span class="mw-page-title-main">Myrmecophagidae</span> Family of mammals

The Myrmecophagidae are a family of anteaters, the name being derived from the Ancient Greek words for 'ant' and 'eat'. Two genera and three species are in the family, consisting of the giant anteater, and the tamanduas. The fossil Eurotamandua from the Messel Pit in Germany may be an early anteater, but its status is currently debated.

<span class="mw-page-title-main">Pygmy three-toed sloth</span> Species of mammals related to anteaters and armadillos

The pygmy three-toed sloth, also known as the monk sloth or dwarf sloth, is a species of sloth in the family Bradypodidae. The species is endemic to Isla Escudo de Veraguas, a small island off the Caribbean coast of Panama. The species was first described by Robert P. Anderson of the University of Kansas and Charles O. Handley Jr., of the Smithsonian Institution in 2001. The pygmy three-toed sloth is significantly smaller than the other three members of its genus, but otherwise resembles the brown-throated three-toed sloth. According to Anderson and Handley Jr., the head-and-body length is between 48 and 53 centimetres, and the body mass ranges from 2.5 to 3.5 kg.

<span class="mw-page-title-main">Anteater</span> Mammals known for eating ants and termites

Anteaters are the four extant mammal species in the suborder Vermilingua, commonly known for eating ants and termites. The individual species have other names in English and other languages. Together with sloths, they are within the order Pilosa. The name "anteater" is also commonly applied to the unrelated aardvark, numbat, echidnas, and pangolins, although they are not closely related to them.

The mammalian order Pilosa, which includes the sloths and anteaters, includes various species from the Caribbean region. Many species of sloths are known from the Greater Antilles, all of which became extinct over the last millennia, but some sloths and anteaters survive on islands closer to the mainland.

<span class="mw-page-title-main">Arthropods associated with sloths</span>

A large number of arthropods are associated with sloths. These include biting and blood-sucking flies such as mosquitoes and sandflies, triatomine bugs, lice, ticks and mites. The sloth’s fur forms a micro-ecozone inhabited by green algae and hundreds of insects. Sloths have a highly specific community of commensal beetles, mites and moths.

References

  1. Gardner, A. L. (2005). "Order Pilosa". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 101. ISBN   978-0-8018-8221-0. OCLC   62265494.
  2. Chiarello, A.; Plese, T. (2014). "Choloepus didactylus". IUCN Red List of Threatened Species . 2014: e.T4777A47439542. doi: 10.2305/IUCN.UK.2014-1.RLTS.T4777A47439542.en . Retrieved 19 November 2021.
  3. Linnæus, Carl (1758). Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I (in Latin) (10th ed.). Holmiæ: Laurentius Salvius. p. 35. Retrieved 23 November 2012.
  4. Trinca, Cristiano Trapé; Palmeira, Francesca Belem Lopes; de Sousa e Silva Júnior, José (2006-05-01). "A Southern Extension of the Geographic Distribution of the Two-Toed Sloth, Choloepus didactylus (Xenarthra, Megalonychidae)". Edentata. 7: 7–9. doi: 10.1896/1413-4411.7.1.7 . ISSN   1413-4411.
  5. 1 2 3 4 5 6 7 8 "Choloepus didactylus (Linnaeus, 1758)". www.gbif.org. Retrieved 2023-09-19.
  6. 1 2 3 McAfee, Robert K.; Naples, Virginia L. (2012-01-01). "NOTICE ON THE OCCURRENCE OF SUPERNUMERARY TEETH IN THE TWO-TOED SLOTHS Choloepus didactylus AND C. hoffmanni". Mastozoología Neotropical. Retrieved 2015-11-20.
  7. 1 2 3 4 5 Adam, Peter J. (December 1999). "Mammalian Species Choloepus didactylus". American Society of Mammalogists.
  8. Stewart, Melissa (November–December 2004). "At the Zoo: Slow and Steady Sloths". Zoogoer. Smithsonian Institution. Archived from the original on 7 June 2011. Retrieved 23 November 2012.
  9. 1 2 Richard-Hansen, C.; Vié, J.-C.; Vidal, N.; Kéravec, J. (1999-04-01). "Body measurements on 40 species of mammals from French Guiana". Journal of Zoology. 247 (4): 419–428. doi:10.1111/j.1469-7998.1999.tb01005.x. ISSN   1469-7998.
  10. 1 2 Vendl, C.; Frei, S.; Dittmann, M. T.; Furrer, S.; Osmann, C.; Ortmann, S.; Munn, A.; Kreuzer, M.; Clauss, M. (June 2016). "Digestive physiology, metabolism and methane production of captive Linné's two-toed sloths ( Choloepus didactylus )". Journal of Animal Physiology and Animal Nutrition. 100 (3): 552–564. doi: 10.1111/jpn.12356 . PMID   26122705.
  11. Dill-McFarland, Kimberly A.; Weimer, Paul J.; Pauli, Jonathan N.; Peery, M. Zachariah; Suen, Garret (May 2016). "Diet specialization selects for an unusual and simplified gut microbiota in two- and three-toed sloths: Gut microbiotas of two- and three-toed sloths". Environmental Microbiology. 18 (5): 1391–1402. doi:10.1111/1462-2920.13022. PMID   26271635.