Acratocnus

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Acratocnus
Temporal range: Late Pleistocene (Rancholabrean)
~0.126–0.011  Ma
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Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Pilosa
Family: Megalocnidae
Genus: Acratocnus
Anthony 1916
Type species
Acratocnus odontrigonus
Anthony, 1916
Species
  • A. antillensisMatthew 1931
  • A. odontrigonusAnthony 1916
  • A. yeMacPhee et al. 2000
Synonyms

HabanocnusMayo, 1978

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

Contents

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]

See also

Related Research Articles

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<i>Parocnus</i> Extinct genus of ground sloths

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References

  1. 1 2 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. Bibcode:2019NatEE...3.1121P. doi:10.1038/s41559-019-0909-z. PMID   31171860. S2CID   174813630.
  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 . hdl: 11336/136908 . 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.
  4. 1 2 3 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 . National Academy of Sciences. 102 (33): 11763–11768. Bibcode:2005PNAS..10211763S. doi: 10.1073/pnas.0502777102 . PMC   1187974 . PMID   16085711.