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Comparing Dirichlet normal surface energy of tooth crowns, a new technique of molar shape quantification for dietary inference, with previous methods in isolation and in combination.

Publication ,  Journal Article
Bunn, JM; Boyer, DM; Lipman, Y; St Clair, EM; Jernvall, J; Daubechies, I
Published in: American journal of physical anthropology
June 2011

Inferred dietary preference is a major component of paleoecologies of extinct primates. Molar occlusal shape correlates with diet in living mammals, so teeth are a potentially useful structure from which to reconstruct diet in extinct taxa. We assess the efficacy of Dirichlet normal energy (DNE) calculated for molar tooth surfaces for reflecting diet. We evaluate DNE, which uses changes in normal vectors to characterize curvature, by directly comparing this metric to metrics previously used in dietary inference. We also test whether combining methods improves diet reconstructions. The study sample consisted of 146 lower (mandibular) second molars belonging to 24 euarchontan taxa. Five shape quantification metrics were calculated on each molar: DNE, shearing quotient, shearing ratio, relief index, and orientation patch count rotated (OPCR). Statistical analyses were completed for each variable to assess effects of taxon and diet. Discriminant function analysis was used to assess ability of combinations of variables to predict diet. Values differ significantly by diets for all variables, although shearing ratios and OPCR do not distinguish statistically between insectivores and folivores or omnivores and frugivores. Combined analyses were much more effective at predicting diet than any metric alone. Alone, relief index and DNE were most effective at predicting diet. OPCR was the least effective alone but is still valuable as the only quantitative measure of surface complexity. Of all methods considered, DNE was the least methodologically sensitive, and its effectiveness suggests it will be a valuable tool for dietary reconstruction.

Duke Scholars

Published In

American journal of physical anthropology

DOI

EISSN

1096-8644

ISSN

0002-9483

Publication Date

June 2011

Volume

145

Issue

2

Start / End Page

247 / 261

Related Subject Headings

  • X-Ray Microtomography
  • Tupaia
  • Tooth Wear
  • Tooth Crown
  • Strepsirhini
  • Molar
  • Image Processing, Computer-Assisted
  • Diet
  • Anthropology
  • Animals
 

Citation

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Bunn, J. M., Boyer, D. M., Lipman, Y., St Clair, E. M., Jernvall, J., & Daubechies, I. (2011). Comparing Dirichlet normal surface energy of tooth crowns, a new technique of molar shape quantification for dietary inference, with previous methods in isolation and in combination. American Journal of Physical Anthropology, 145(2), 247–261. https://doi.org/10.1002/ajpa.21489
Bunn, Jonathan M., Doug M. Boyer, Yaron Lipman, Elizabeth M. St Clair, Jukka Jernvall, and Ingrid Daubechies. “Comparing Dirichlet normal surface energy of tooth crowns, a new technique of molar shape quantification for dietary inference, with previous methods in isolation and in combination.American Journal of Physical Anthropology 145, no. 2 (June 2011): 247–61. https://doi.org/10.1002/ajpa.21489.
Bunn JM, Boyer DM, Lipman Y, St Clair EM, Jernvall J, Daubechies I. Comparing Dirichlet normal surface energy of tooth crowns, a new technique of molar shape quantification for dietary inference, with previous methods in isolation and in combination. American journal of physical anthropology. 2011 Jun;145(2):247–61.
Bunn, Jonathan M., et al. “Comparing Dirichlet normal surface energy of tooth crowns, a new technique of molar shape quantification for dietary inference, with previous methods in isolation and in combination.American Journal of Physical Anthropology, vol. 145, no. 2, June 2011, pp. 247–61. Epmc, doi:10.1002/ajpa.21489.
Bunn JM, Boyer DM, Lipman Y, St Clair EM, Jernvall J, Daubechies I. Comparing Dirichlet normal surface energy of tooth crowns, a new technique of molar shape quantification for dietary inference, with previous methods in isolation and in combination. American journal of physical anthropology. 2011 Jun;145(2):247–261.
Journal cover image

Published In

American journal of physical anthropology

DOI

EISSN

1096-8644

ISSN

0002-9483

Publication Date

June 2011

Volume

145

Issue

2

Start / End Page

247 / 261

Related Subject Headings

  • X-Ray Microtomography
  • Tupaia
  • Tooth Wear
  • Tooth Crown
  • Strepsirhini
  • Molar
  • Image Processing, Computer-Assisted
  • Diet
  • Anthropology
  • Animals