Beyond Gorilla and Pongo: Alternative models for evaluating variation and sexual dimorphism in fossil hominoid samples
Article first published online: 8 APR 2009
Copyright © 2009 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 140, Issue 2, pages 253–264, October 2009
How to Cite
Scott, J. E., Schrein, C. M. and Kelley, J. (2009), Beyond Gorilla and Pongo: Alternative models for evaluating variation and sexual dimorphism in fossil hominoid samples. Am. J. Phys. Anthropol., 140: 253–264. doi: 10.1002/ajpa.21059
- Issue published online: 3 SEP 2009
- Article first published online: 8 APR 2009
- Manuscript Accepted: 28 JAN 2009
- Manuscript Received: 3 JUL 2008
- dental variation;
Sexual size dimorphism in the postcanine dentition of the late Miocene hominoid Lufengpithecus lufengensis exceeds that in Pongo pygmaeus, demonstrating that the maximum degree of molar size dimorphism in apes is not represented among the extant Hominoidea. It has not been established, however, that the molars of Pongo are more dimorphic than those of any other living primate. In this study, we used resampling-based methods to compare molar dimorphism in Gorilla, Pongo, and Lufengpithecus to that in the papionin Mandrillus leucophaeus to test two hypotheses: (1) Pongo possesses the most size-dimorphic molars among living primates and (2) molar size dimorphism in Lufengpithecus is greater than that in the most dimorphic living primates. Our results show that M. leucophaeus exceeds great apes in its overall level of dimorphism and that L. lufengensis is more dimorphic than the extant species. Using these samples, we also evaluated molar dimorphism and taxonomic composition in two other Miocene ape samples—Ouranopithecus macedoniensis from Greece, specimens of which can be sexed based on associated canines and P3s, and the Sivapithecus sample from Haritalyangar, India. Ouranopithecus is more dimorphic than the extant taxa but is similar to Lufengpithecus, demonstrating that the level of molar dimorphism required for the Greek fossil sample under the single-species taxonomy is not unprecedented when the comparative framework is expanded to include extinct primates. In contrast, the Haritalyangar Sivapithecus sample, if itrepresents a single species, exhibits substantially greater molar dimorphism than does Lufengpithecus. Given these results, the taxonomic status of this sample remains equivocal. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc.