A New Genus of Megalonychid Ground Sloth (Mammalia, Xenarthra) from the Late Pleistocene of Quintana Roo, Mexico

@article{McDonald2017ANG,
  title={A New Genus of Megalonychid Ground Sloth (Mammalia, Xenarthra) from the Late Pleistocene of Quintana Roo, Mexico},
  author={H. Gregory McDonald and James C. Chatters and Timothy J. Gaudin},
  journal={Journal of Vertebrate Paleontology},
  year={2017},
  volume={37}
}
ABSTRACT A new genus and species of late Pleistocene megalonychid sloth, Nohochichak xibalbahkah, gen. et sp. nov., is described from Hoyo Negro, a chamber in the Sac Actun cave system, Quintana Roo, Mexico. Phylogenetic analysis indicates that this new sloth is most closely related to Meizonyx salvadorensis from the middle Pleistocene of El Salvador, and that these two genera in turn are the sister clade to Megistonyx and Ahytherium in South America and not the other North American… 

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References

SHOWING 1-10 OF 61 REFERENCES

New Megalonychid Sloths (Phyllophaga, Xenarthra) from the Quaternary of Hispaniola

It is inferred that the later subdivision and subsidence of major portions of GAARlandia must have finely vicariated its biota (which included sloths at least as early as the Early Oligocene), consistent with several new lines of evidence concerning the paleontological and paleogeographical history of the Caribbean region.

A new genus and species of nothrotheriid sloth (Xenarthra, Tardigrada, Nothrotheriidae) from the Late Miocene (Huayquerian) of Peru

Phylogenetic analysis places the new genus and species of nothrotheriine sloth from riverbank deposits of the Río Acre region of Peru in western Amazonia as sister group to the (Pronothrotherium (NothroTheriops + Nothratherium)) clade.

New Pleistocene remains of megalonychid ground sloths (Xenarthra: Pilosa) from the intertropical Brazilian region

Comparisons of the mandible and ossicles are conducted with homologous elements of the contemporaneous and sympatric Ahytherium aureum Cartelle, De Iuliis, and Pujos, 2008, and reinforce the distinction between these two species detailed in their initial descriptions.

Premaxillae of the Extinct Megalonychid Sloths Acratocnus, Neocnus, and Megalonyx, and their Phylogenetic Implications (Mammalia, Xenarthra)

Morphological evidence suggests that a broadened, plate-like premaxilla constitutes a synapomorphy for the entire clade Megalonychidae, and the loss of this process may unite late Miocene to Recent megalonychids.

Nothrotheriops shastensis (Sinclair) from Actun Lak: First Record of Nothrotheriidae (Mammalia, Xenarthra, Pilosa) from Belize

Abstract. Sloth remains recovered from Actun Lak, Cayo District, Belize, during archaeological excavations by the Pacbitun Regional Archaeological Project include numerous though mainly fragmentary

Phylogenetic relationships among sloths (Mammalia, Xenarthra, Tardigrada): the craniodental evidence

The results imply that the split between the two extant sloth genera is ancient, dating back perhaps as much as 40 Myr, and that the similarities between these two taxa present one of the most dramatic examples of convergent evolution known among mammals.

The ear region of edentates and the phylogeny of the Tardigrada (Mammalia, Xenarthra)

A cladistic investigation of the phylogenetic relationships among 21 extinct and extant genera of sloths was performed on the basis of characteristics of the bony anatomy of the auditory region in order to evaluate specific hypotheses of relationship within the group.

The Edentata of North America

  • E. Cope
  • Geology
    The American Naturalist
  • 1889
Of these divisions it is evident hat the Nomarthra are the least specialized, and must be regarded as ancestral to the Xenarthra, which are now exclusively Old World, while the Xexartkra are confined to the New World.
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