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The evolution of molar occlusion in the Cercopithecidae and early Catarrhines.

Publication ,  Journal Article
Kay, RF
Published in: American journal of physical anthropology
March 1977

Those Eocene prosimians which are possible catarrhine ancestors have four blade-like crests on each lower molar. Each crest shears in sequence across two upper molar crests. Occluding crests are concavely curved to hold the foods being sheared. Each of two medial lower molar crests bordering the principal crushing surface shear past single upper molar crests at about the same time the lateral lower molar crests contact the second rank of upper molar crests. Grinding and crushing areas are restricted to hypoconid, trigonid, and protocone surfaces. Oligocene catarrhine molars have increased crushing-grinding capacities and maintained but modify their shearing. As the crushing surface of the protocone expands and a crushing hypocone is added, the "second rank" upper molar shearing crests are functionally reduced. At the same time medial crests are increasingly emphasized so that the total shearing capacity remains virtually unchanged. Marginal shearing blades are straight edged; leading edges of occluding blades are set at different angles to the occlusal plane so that blades contact at only one point at any given time. Early Primates have separate crushing basins surrounded by shearing blades. Catarrhines tend to link explanding crushing surfaces anteroposteriorly into a continuous surface between all molars. A cladistic analysis based on both new and previously recognized characters indicates that: 1. Apidium may be more closely related to Aegyptopithecus than to Parapithecus; 2. cercopithecids are derived from a Parapithecus-related stock; 3. Oreopithecus could equally well have come from an Apidium or Aegyptopithecus stock.

Duke Scholars

Published In

American journal of physical anthropology

DOI

EISSN

1096-8644

ISSN

0002-9483

Publication Date

March 1977

Volume

46

Issue

2

Start / End Page

327 / 352

Related Subject Headings

  • Primates
  • Paleodontology
  • Molar
  • History, Ancient
  • Dental Occlusion
  • Biological Evolution
  • Anthropology
  • Animals
  • 4401 Anthropology
  • 4301 Archaeology
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Kay, R. F. (1977). The evolution of molar occlusion in the Cercopithecidae and early Catarrhines. American Journal of Physical Anthropology, 46(2), 327–352. https://doi.org/10.1002/ajpa.1330460213
Kay, R. F. “The evolution of molar occlusion in the Cercopithecidae and early Catarrhines.American Journal of Physical Anthropology 46, no. 2 (March 1977): 327–52. https://doi.org/10.1002/ajpa.1330460213.
Kay RF. The evolution of molar occlusion in the Cercopithecidae and early Catarrhines. American journal of physical anthropology. 1977 Mar;46(2):327–52.
Kay, R. F. “The evolution of molar occlusion in the Cercopithecidae and early Catarrhines.American Journal of Physical Anthropology, vol. 46, no. 2, Mar. 1977, pp. 327–52. Epmc, doi:10.1002/ajpa.1330460213.
Kay RF. The evolution of molar occlusion in the Cercopithecidae and early Catarrhines. American journal of physical anthropology. 1977 Mar;46(2):327–352.
Journal cover image

Published In

American journal of physical anthropology

DOI

EISSN

1096-8644

ISSN

0002-9483

Publication Date

March 1977

Volume

46

Issue

2

Start / End Page

327 / 352

Related Subject Headings

  • Primates
  • Paleodontology
  • Molar
  • History, Ancient
  • Dental Occlusion
  • Biological Evolution
  • Anthropology
  • Animals
  • 4401 Anthropology
  • 4301 Archaeology