PhD: Ecological drivers and evolutionary patterns: diet, feeding, evolution and extinction in conodonts

Diet, trophic niche, and feeding mechanisms are major evolutionary drivers, but robust, fossil-based analysis of their influence on evolutionary patterns, and how they change through major extinctions, is challenging. Conodont teeth are abundant and diverse, and the fossil record of this long-lived group of primitive vertebrates is among the best of any group of organisms. In many ways conodonts are ideal for investigating links between ecological and evolutionary patterns and major extinctions through the Palaeozoic and Triassic, but such research has been hampered by our lack of palaeobiological understanding. How conodont tooth morphology is related to diet, for example, was effectively unknown. New methods of analysis are changing this.

Work pioneered in Leicester (Purnell 1995; Purnell and Jones 2012) has demonstrated that wear and surface damage on conodont teeth is common and closely related to differences in feeding mechanisms and diet. Quantitative analysis can thus reveal dietary changes through time, and differences between taxa. Similarly, new approaches to analysis of tooth complexity and how it relates to diet (Evans et al. 2007) can be applied to conodonts, providing an additional, independent test of trophic ecology.

By combining analyses of conodont tooth function and diet with robust tests for biases in their fossil record, this project will investigate the relationship between trophic ecology, diversity, and evolutionary patterns. This completely novel approach will determine how extinction risk varies between different trophic guilds of conodonts, and how survival and diversification vary with trophic ecology. The results will provide a new proxy for ecosystem collapse and recovery through the three mass extinction events that conodonts survived.

Quantitative approaches lie at the core of this project, so you should be numerate and keen to engage with statistical methods of analysis. Although there are key questions and a series of well-constrained analyses at its core, this project also offers scope for an excellent student to develop the research in new directions. At Leicester you will join a dynamic group of researchers and students developing novel approaches to analysis of diet and trophic niche in fossil vertebrates.

References
Purnell, M. A. 1995: Microwear on conodont elements and macrophagy in the first vertebrates. Nature 374, 798-800.
Purnell, M. A. & Donoghue, P. C. J. 2005: Between death and data: biases in interpretation of the fossil record of conodonts. In Purnell, M. A. & Donoghue, P. C. J. (ed.): Conodont biology and phylogeny - interpreting the fossil record. Special Papers in Palaeontology 73, 7-25. Palaeontological Association,
Purnell, M. A. & Jones, D. O. 2012: Quantitative analysis of conodont tooth wear and damage as a test of ecological and functional hypotheses. Paleobiology 38, 605-626.
Murdock, D. J. E., Sansom, I. J. & Donoghue, P. C. J. 2013: Cutting the first ‘teeth’: a new approach to functional analysis of conodont elements. Proceedings of the Royal Society B: Biological Sciences 280,
Evans, A. R., Wilson, G. P., Fortelius, M. & Jernvall, J. 2007: High-level similarity of dentitions in carnivorans and rodents. Nature 445, 78-81.