Skip to main content

Enamel-dentine junction morphology in hominin mandibular third premolars

Davies, Thomas (2018) Enamel-dentine junction morphology in hominin mandibular third premolars. Master of Science by Research (MScRes) thesis, University of Kent,. (Access to this publication is currently restricted. You may be able to access a copy if URLs are provided)

PDF
Restricted to Repository staff only until May 2021.
Contact us about this Publication Download (2MB)
[img]

Abstract

In non-human apes, as in most catarrhines, the P3 is adapted for a role in honing the large upper canine, a feature which was lost early in hominin evolution. No longer adaptively constrained to the morphology required for canine honing, the hominin P3 evolved in a variety of ways, mostly to improve its masticatory ability. This change in function makes the P3 a particularly important tooth position in hominin evolution and it has featured prominently in systematic analyses of the hominin clade. However, due to dental wear much of the original morphology of the P3 crown is lost in many hominin teeth. Analyses of other tooth positions have demonstrated that examining the enamel-dentine junction (EDJ) can improve the taxonomic signal in tooth crown morphology as well as reveal detailed insights into the presence and manifestation of discrete dental traits.

This study uses geometric morphometric techniques to analyse the shape of the P3 EDJ in a broad sample of fossil hominins, modern humans, and extant non-human apes (n = 118), aiming to characterise the major differences in P3 morphology between apes and hominins, and then within the hominin clade. The study also tests the utility of P3 EDJ shape for distinguishing among major hominin species, and addresses the affinities of a number of hominin specimens of uncertain taxonomic affiliation. Moreover, the EDJ expression of a number of P3 discrete traits are identified and investigated for the first time.

The results suggest that the morphology of the P3 EDJ is effective in distinguishing among taxa, with a very high level of classification accuracy. Further, P3 morphology is linked to previously discussed trends in hominin evolution such as the unique dental adaptations seen in Paranthropus species. The EDJ expression of discrete traits such as the transverse crest, buccal grooves and the marginal ridge are found to be variable among taxonomic groups. Potential developmental links to other features identified in molars are discussed.

Item Type: Thesis (Master of Science by Research (MScRes))
Thesis advisor: Skinner, Matthew
Thesis advisor: Kivell, Tracy
Uncontrolled keywords: Paleoanthropology, Hominin evolution, Taxonomy, Dental morphology, Enamel-dentine junction morphology, Geometric morphometrics
Divisions: Faculties > Social Sciences > School of Anthropology and Conservation
SWORD Depositor: System Moodle
Depositing User: System Moodle
Date Deposited: 27 Jun 2018 10:10 UTC
Last Modified: 01 Aug 2019 10:43 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/67420 (The current URI for this page, for reference purposes)
  • Depositors only (login required):

Downloads

Downloads per month over past year