Editing Ground sloth (section)

== Description ==
[[File:Ground sloth size comparison.png|thumb|Size comparison of various ground sloths compared to a human, including ''[[Megatherium|Megatherium americanum]]'' (A, top left) ''[[Eremotherium laurillardi]]'' (B, top right), ''[[Lestodon armatus]]'' (C, middle left) ''[[Mylodon darwinii]]'' (D, middle right) ''[[Glossotherium robustum]]'' (E, bottom left) and ''[[Catonyx|Catonyx cf. C. cuvieri]]'' (F, bottom right)]]
Ground sloths varied widely in size from under {{Convert|100|kg|lb}} in the Caribbean ground sloths, to {{Convert|3700-4100|kg|lb}} in the largest ground sloth genera ''[[Megatherium]]'', ''[[Lestodon]]'' and ''[[Eremotherium]].''<ref name=":4" /><ref>{{Cite journal |last1=Bargo |first1=M. Susana |last2=Vizcaíno |first2=Sergio F. |last3=Archuby |first3=Fernando M. |last4=Blanco |first4=R. Ernesto |date=2000-09-25 |title=Limb bone proportions, strength and digging in some Lujanian (Late Pleistocene-Early Holocene) mylodontid ground sloths (Mammalia, Xenarthra) |url=http://www.tandfonline.com/doi/abs/10.1671/0272-4634%282000%29020%5B0601%3ALBPSAD%5D2.0.CO%3B2 |journal=Journal of Vertebrate Paleontology |language=en |volume=20 |issue=3 |pages=601–610 |doi=10.1671/0272-4634(2000)020[0601:LBPSAD]2.0.CO;2 |issn=0272-4634|url-access=subscription }}</ref> The bodies of ground sloths were generally barrel-shaped, with a broad pelvis.<ref name=":9">{{Cite journal |last=Naish |first=Darren |date=November 2005 |title=Fossils explained 51: Sloths |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2451.2005.00538.x |journal=Geology Today |language=en |volume=21 |issue=6 |pages=232–238 |doi=10.1111/j.1365-2451.2005.00538.x |issn=0266-6979|url-access=subscription }}</ref> The skull shapes of ground sloths are highly variable.<ref name=":10" /> Like other xenarthrans, the adult teeth of ground sloths lacked [[Tooth enamel|enamel]], with the tooth surface being composed of relatively soft [[Dentin|orthodentine]].<ref>Resar, N. A., Green, J. L., & McAfee, R. K. (2013). Reconstructing paleodiet in ground sloths (Mammalia, Xenarthra) using dental microwear analysis. ''Kirtlandia,'' ''58,'' 61–72.</ref> The number of teeth in the jaws is considerably reduced in comparison to other mammals, with most ground sloths only having 5 and 4 teeth in each half of the upper and lower jaws respectively, with some ground sloths exhibiting further tooth number reduction.<ref name=":7">{{Cite journal |last1=Hautier |first1=Lionel |last2=Gomes Rodrigues |first2=Helder |last3=Billet |first3=Guillaume |last4=Asher |first4=Robert J. |date=2016-06-14 |title=The hidden teeth of sloths: evolutionary vestiges and the development of a simplified dentition |journal=Scientific Reports |language=en |volume=6 |issue=1 |page=27763 |doi=10.1038/srep27763 |issn=2045-2322 |pmc=4906291 |pmid=27297516|bibcode=2016NatSR...627763H }}</ref> These teeth were rootless<ref name=":7" /> and were continuously growing (hypselodont), and typically have a relatively simple morphology.<ref name=":10" /> There are generally no teeth at the front of the jaws. In order to be able to grasp food, those whose skulls exhibit narrow muzzles are likely to have had prehensile, [[black rhinoceros]]-like upper lips, while those with wider muzzles are likely to have had a square, [[white rhinoceros]] like upper-lip, used in combination with mobile tongues.<ref name=":10">{{Cite journal |last1=Bargo |first1=M. Susana |last2=Toledo |first2=Néstor |last3=Vizcaíno |first3=Sergio F. |date=February 2006 |title=Muzzle of South American Pleistocene ground sloths (Xenarthra, Tardigrada) |url=https://onlinelibrary.wiley.com/doi/10.1002/jmor.10399 |journal=Journal of Morphology |language=en |volume=267 |issue=2 |pages=248–263 |doi=10.1002/jmor.10399 |pmid=16315216 |issn=0362-2525|url-access=subscription }}</ref> Some ground sloths have canine-like teeth at the front of the jaws separated from the other teeth by a gap (diastema).<ref name=":9" /> The hands of ground sloths have [[ungual]] phalanges that indicate that they had well developed claws.<ref>{{Cite journal |last1=Patiño |first1=Santiago J. |last2=Fariña |first2=Richard A. |date=2017-11-17 |title=Ungual phalanges analysis in Pleistocene ground sloths (Xenarthra, Folivora) |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2017.1286653 |journal=Historical Biology |language=en |volume=29 |issue=8 |pages=1065–1075 |doi=10.1080/08912963.2017.1286653 |bibcode=2017HBio...29.1065P |issn=0891-2963|url-access=subscription }}</ref> In many ground sloth families (Megatheriidae, Mylodontidae, Scelidotheriidae and Nothrotheriidae), the hindfoot is inwardly rotated, meaning sole faces inwards and that the body weight was primarily borne on the fifth [[Metatarsal bones|metatarsus]] and the [[calcaneum]].<ref>H.G. McDonald [https://books.google.com/books?id=bGbmCQAAQBAJ&dq=ground+sloth+walking&pg=PA201 Biomechanical inferences of locomotion in ground sloths: integrating morphological and track data]. New Mexico Mus Nat. Hist. Sci. Bull., 42 (2007), pp. 201-208</ref>