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Chewing Through the Miocene: An Examination of the Feeding Musculature in the Ground Sloth Hapalops from South America (Mammalia: Pilosa)
F1000Res
  • Virginia L Naples
  • Robert McAfee, Philadelphia College of Osteopathic Medicine
Document Type
Article
Publication Date
1-1-2014
Abstract
Hapalops, a smaller-sized and early sloth of the Megatheroidea, appeared in the middle Miocene Santa Cruz formation of Argentina. This genus is part of the group from which later, larger megatheroids arose, i.e., Nothrotheriops and Megatherium. Many cranial characters support this idea; however Hapalops is not merely a smaller antecedent of the later forms. Specifically, Hapalops retains short anterior caniniform teeth, and a temporomandibular joint elevated above the cheek tooth row; a combination distinct among sloths. An elevated temporomandibular joint occurs in Bradypus, a tree sloth with anterior chisel-shaped teeth instead of caniniforms, and the tree sloth Choloepus, which is aligned with the megalonychids, has anterior caniniforms. Hapalops has an elongated zygomatic ascending process that is reminiscent of that in Bradypus; however, the Bradypus skull is extremely foreshortened while that of Hapalops is elongated, as in nothrotheres, but not deepened as in megatheres. Previous work identified many sloth cranial character complexes, and functional limitations on skull feature combinations. The unique Hapalops character patterns indicate a selective feeder with a mediolaterally oriented grinding stroke during mastication.
PubMed ID
25075299
Comments

This article was published in F1000Research, Volume 3, Issue , Pages 86- .

The published version is available at http://dx.doi.org/10.12688/f1000research.3282.1.

Copyright © 2014. CC BY 3.0.

Citation Information
Virginia L Naples and Robert McAfee. "Chewing Through the Miocene: An Examination of the Feeding Musculature in the Ground Sloth Hapalops from South America (Mammalia: Pilosa)" F1000Res Vol. 3 (2014) p. 86 - 86
Available at: http://works.bepress.com/robert-mcafee/2/