Acratocnus

Acratocnus; Temporal range: Late Pleistocene (Rancholabrean); ~0.126–0.011 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Pilosa
Family:	†Megalocnidae
Genus:	†Acratocnus; Anthony 1916
Type species
	Acratocnus odontrigonus; Anthony, 1916
Species
	†A. antillensis Matthew 1931; †A. odontrigonus Anthony 1916; †A. ye MacPhee et al. 2000;
Synonyms
	Habanocnus Mayo, 1978

Acratocnus is an extinct genus of ground sloths that were found on Cuba, Hispaniola (today the Dominican Republic and Haiti), and Puerto Rico.

Classification

Like all of the Antillean sloths, Acratocnus was formerly thought on the basis of morphological evidence to be a member of the family Megalonychidae, which was also thought to include Choloepus, the two-toed tree sloths. Recent molecular evidence has clarified that Caribbean sloths represent a separate basal branch of the sloth radiation,^[1]^[2] now placed in the family Megalocnidae.^[1]

Location

Fossils of Acratocnus were found on the islands of Puerto Rico, Cuba, and Hispaniola, where they inhabited the montane forests of the highlands. The Puerto Rican ground sloth, Acratocnus odontrigonus is known from several poorly documented cave excavations in northwestern Puerto Rico. The various species are regarded as being semi-arboreal because of their (relatively speaking) small size and their large hooked claws.

Size

The various species of Acratocnus ranged in weight from 50 to 150 pounds (23 to 68 kg), and were thus much larger than living tree sloths (genera Choloepus and Bradypus), which do not exceed 20 pounds (9.1 kg).^{[citation needed]}

Extinction

As with many sloth fossils, these species of sloth have not been radiometrically dated.^[3] It is suggested^{[by whom?]} that the Puerto Rican and Hispaniolan Acratocnus species survived into the late Pleistocene but disappeared by the mid-Holocene.^{[citation needed]} The related Cuban ground sloth, Megalocnus rodens, survived until at least c. 6600 BP,^[4] and the latest survival reported for any of the Antillean sloths is c. 5000 BP, for the Hispaniolan Neocnus comes,^[4] based on AMS radiocarbon dating. The cause(s) of their extinctions may have been climatic changes, or more likely, human hunting by the indigenous peoples of the Caribbean.^[4]

References

^ ^a ^b Presslee, S.; Slater, G. J.; Pujos, F.; Forasiepi, A. M.; Fischer, R.; Molloy, K.; Mackie, M.; Olsen, J. V.; Kramarz, A.; Taglioretti, M.; Scaglia, F.; Lezcano, M.; Lanata, J. L.; Southon, J.; Feranec, R.; Bloch, J.; Hajduk, A.; Martin, F. M.; Gismondi, R. S.; Reguero, M.; de Muizon, C.; Greenwood, A.; Chait, B. T.; Penkman, K.; Collins, M.; MacPhee, R.D.E. (2019). "Palaeoproteomics resolves sloth relationships" (PDF). Nature Ecology & Evolution. 3 (7): 1121–1130. doi:10.1038/s41559-019-0909-z. PMID 31171860. S2CID 174813630.
^ Delsuc, F.; Kuch, M.; Gibb, G. C.; Karpinski, E.; Hackenberger, D.; Szpak, P.; Martínez, J. G.; Mead, J. I.; McDonald, H. G.; MacPhee, R.D.E.; Billet, G.; Hautier, L.; Poinar, H. N. (2019). "Ancient Mitogenomes Reveal the Evolutionary History and Biogeography of Sloths". Current Biology. 29 (12): 2031–2042.e6. doi:10.1016/j.cub.2019.05.043. PMID 31178321.
^ Donald A. McFarlane (1999). "Late Quaternary Fossil Mammals and Last Occurrence Dates from Caves at Barahona, Puerto Rico" (PDF). Caribbean Journal of Science. 35 (3–4): 238–248. Archived from the original (PDF) on 2011-07-20. Retrieved 29 May 2022.
^ ^a ^b ^c Steadman, D. W.; Martin, P. S.; MacPhee, R. D. E.; Jull, A. J. T.; McDonald, H. G.; Woods, C. A.; Iturralde-Vinent, M.; Hodgins, G. W. L. (2005-08-16). "Asynchronous extinction of late Quaternary sloths on continents and islands". Proc. Natl. Acad. Sci. USA. 102 (33). National Academy of Sciences: 11763–11768. Bibcode:2005PNAS..10211763S. doi:10.1073/pnas.0502777102. PMC 1187974. PMID 16085711.

[Presslee2019-1] Presslee, S.; Slater, G. J.; Pujos, F.; Forasiepi, A. M.; Fischer, R.; Molloy, K.; Mackie, M.; Olsen, J. V.; Kramarz, A.; Taglioretti, M.; Scaglia, F.; Lezcano, M.; Lanata, J. L.; Southon, J.; Feranec, R.; Bloch, J.; Hajduk, A.; Martin, F. M.; Gismondi, R. S.; Reguero, M.; de Muizon, C.; Greenwood, A.; Chait, B. T.; Penkman, K.; Collins, M.; MacPhee, R.D.E. (2019). "Palaeoproteomics resolves sloth relationships" (PDF). Nature Ecology & Evolution. 3 (7): 1121–1130. doi:10.1038/s41559-019-0909-z. PMID 31171860. S2CID 174813630.

[Delsuc2019-2] Delsuc, F.; Kuch, M.; Gibb, G. C.; Karpinski, E.; Hackenberger, D.; Szpak, P.; Martínez, J. G.; Mead, J. I.; McDonald, H. G.; MacPhee, R.D.E.; Billet, G.; Hautier, L.; Poinar, H. N. (2019). "Ancient Mitogenomes Reveal the Evolutionary History and Biogeography of Sloths". Current Biology. 29 (12): 2031–2042.e6. doi:10.1016/j.cub.2019.05.043. PMID 31178321.

[3] Donald A. McFarlane (1999). "Late Quaternary Fossil Mammals and Last Occurrence Dates from Caves at Barahona, Puerto Rico" (PDF). Caribbean Journal of Science. 35 (3–4): 238–248. Archived from the original (PDF) on 2011-07-20. Retrieved 29 May 2022.

[Steadman-4] Steadman, D. W.; Martin, P. S.; MacPhee, R. D. E.; Jull, A. J. T.; McDonald, H. G.; Woods, C. A.; Iturralde-Vinent, M.; Hodgins, G. W. L. (2005-08-16). "Asynchronous extinction of late Quaternary sloths on continents and islands". Proc. Natl. Acad. Sci. USA. 102 (33). National Academy of Sciences: 11763–11768. Bibcode:2005PNAS..10211763S. doi:10.1073/pnas.0502777102. PMC 1187974. PMID 16085711.

[1]

[2]

[3]

[4]

Classification

Location

Size

Extinction

See also

References