Scelidotheriidae

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).

Scelidotheriidae Temporal range: Late Oligocene-Late Pleistocene (Deseadan-Lujanian) ~
Scelidotherium leptocephalum in Paris
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Pilosa
Superfamily:	Mylodontoidea
Family:	†Scelidotheriidae Ameghino 1889
Genera
†Analcitherium †Catonyx †Chubutherium †Nematherium †Neonematherium †Proscelidodon †Scelidodon †Scelidotheridium †Scelidotheriops †Scelidotherium †Sibyllotherium †Valgipes

Taxonomy

Together with Mylodontidae, and the two-toed sloths, the scelidotheriids form the superfamily Mylodontoidea. Chubutherium is an ancestral and very plesiomorphic member of this family and does not belong to the main group of closely related genera.

Phylogeny

The following sloth family phylogenetic tree is based on collagen and mitochondrial DNA sequence data (see Fig. 4 of Presslee et al., 2019).

Folivora	† Megalocnidae (Caribbean sloths) Mylodontoidea † Scelidotheriidae † Scelidodon sp. † Scelidotherium sp. † Mylodontidae † Lestodon armatus † Paramylodon harlani † Glossotherium robustus † Mylodon darwinii Choloepodidae (two-toed sloths) Choloepus didactylus Choloepus hoffmanni Megatherioidea † Megalonychidae    Bradypodidae (three-toed sloths) † Nothrotheriidae † Megatheriidae

Below is a more detailed cladogram of the Scelidotheriidae, based on the work of Nieto et al. 2020.

Scelidotheriinae	Sibyllotherium guenguelianum Neonematherium flabellatum Scelidotherium Proscelidodon gracillimus Proscelidodon patrius Proscelidodon rothi Valgipes bucklandi Catonyx cuvieri Catonyx tarijensis Catonyx chiliense

Further reading

• Cuvier, G. (1796): Notice sur le squelette d'une très grande espèce de quadrupède inconnue jusqu'à présent, trouvé au Paraguay, et déposé au cabinet d'histoire naturelle de Madrid. Magasin encyopédique, ou Journal des Sciences, des Lettres et des Arts (1): 303-310; (2): 227-228.
• Iuliis, G.; Cartelle, C. (December 1999). "A new giant megatheriine ground sloth (Mammalia: Xenarthra: Megatheriidae) from the late Blancan to early Irvingtonian of Florida". Zoological Journal of the Linnean Society. 1 27 (4): 495–515. doi:10.1006/zjls.1998.0190.
• Harrington, C.R. (1993): Yukon Beringia Interpretive Center - Jefferson's Ground Sloth. Retrieved 2008-JAN-24.
• Hogan, C.M. (2008): Cueva del Milodon, Megalithic Portal. Retrieved 2008-APR-13
• Kurtén, B.; Anderson, E. (1980). Pleistocene Mammals of North America. Columbia University Press. ISBN 978-0-231-03733-4. OCLC 776120509.
• McKenna, M. C.; Bell, S. K. (1997). Classification of Mammals: Above the Species Level. Columbia University Press. ISBN 978-0-231-52853-5. OCLC 182575570.
• Nowak, R.M. (1999): Walker's Mammals of the World (Vol. 2). Johns Hopkins University Press, London.
• White, J. (1993). "Indicators of locomotor habits in xenarthrans: Evidence for locomotor heterogeneity among fossil sloths". Journal of Vertebrate Paleontology. 13 (2): 230–242. Bibcode:1993JVPal..13..230W. doi:10.1080/02724634.1993.10011502.
• White, J.L.; MacPhee, R.D.E. (2001). "The sloths of the West Indies: a systematic and phylogenetic review". In Woods, C.A.; Sergile, F.E. (eds.). Biogeography of the West Indies: Patterns and Perspectives. Boca Raton, London, New York, and Washington, D.C.: CRC Press. pp. 201–235. doi:10.1201/9781420039481-14. ISBN 978-0-8493-2001-9.
• Woodward, A. S. (January 1900). "On some Remains of Grypotherium (Neomylodori) listai and associated Mammals from a Cavern near Consuelo Cove, Last Hope Inlet, Patagonia". Proceedings of the Zoological Society of London. 69 (1): 64–78. doi:10.1111/j.1096-3642.1890.tb01704.x.

External links

• Sloth World: An Online Sloth Bibliography
• Picture and information about a ground sloth skeleton on display at the University of Georgia's Science Library
• Have some ground sloths survived in Argentina?
• Ground sloths in general
• Western Center for Archaeology and Paleontology Hemet, CA