Variability in Premolar and Molar Root Number in a Modern Population of Pan troglodytes verus
Version of Record online: 20 JUN 2014
© 2014 Wiley Periodicals, Inc.
The Anatomical Record
Volume 297, Issue 10, pages 1927–1934, October 2014
How to Cite
Emonet, E.-G. and Kullmer, O. (2014), Variability in Premolar and Molar Root Number in a Modern Population of Pan troglodytes verus. Anat Rec, 297: 1927–1934. doi: 10.1002/ar.22959
- Issue online: 16 SEP 2014
- Version of Record online: 20 JUN 2014
- Manuscript Accepted: 8 MAY 2014
- Manuscript Revised: 26 DEC 2013
- Manuscript Received: 28 NOV 2012
- Pan troglodytes;
- dental roots;
While teeth are the most common fossil remains for hominoids, little is known of the tooth root morphology in Primates. With the exception of modern humans, the variability of the number of roots within a species is scarcely documented and not conclusively quantified. This lack of knowledge hinders the interpretation of observed evolutionary trends, such as the reduction of the number of roots of premolars within the hominins. Here, we present the first quantification of the variability of the number of roots in a nonhuman ape population including 405 specimens. Our sample is made of a single biological population of Pan troglodytes verus from Liberia, which is compared to other extant hominoids. Both permanent and deciduous teeth were analyzed and comprise premolars and molars from maxillaries and mandibles. The estimated variability is very low for each tooth position; more than 97% of the specimens displaying the same number of roots except for P4 (94%), M1 (89%), and P4 (57%). No variability at all was observed for lacteal teeth. Males and females are statistically identical, and no difference linked to the tooth size (estimated by the occlusal surface) was observed. When compared to the observation in other hominoid species, these results emphasize that the difference of the number of roots observed between modern humans and apes is significant, and suggests that the evolution of premolar root number is mosaic, with the common ancestor of Pan and Homo probably displaying a reduced number of roots for P4 and maybe P3, but a plesiomorphic morphology of the roots of lower premolars. Anat Rec, 297:1927–1934, 2014. © 2014 Wiley Periodicals, Inc.