Project highlights

  • Use cutting edge approaches to analyse conodont feeding mechanisms and interpret the conodont fossil record in terms of their functional ecology and the differential evolutionary success and survival of ecological guilds
  • Exploit the exceptionally good fossil record of conodonts to analyse major evolutionary drivers before, during and after major perturbations in the biosphere
  • Opportunities to travel overseas to collect data from fossil collections.

Overview

The conodont fossil record is among the best of any organisms. The morphological complexity of the teeth of this long-lived group of primitive vertebrates and the rate at which they evolved have made them paramount tools for biostratigraphy, with millions of elements amassed in collections around the world. But the ecological signals entrained in their fossil record are only now starting to be decoded. It is becoming clear that conodonts were more significant components of Palaeozoic and Triassic marine ecosystems than previously thought, potentially outnumbering other fishes and sharks for much of their 300 million year range. Their dental morphology reflects a rich history of dietary adaptation, and the perception that conodonts were small, and restricted to low trophic levels, may be nothing more than a bias imposed by the processes used to extract them from rocks. This project will address major questions of conodont functional ecology through exploration and testing of a number of broad research themes and hypotheses.

Conodont elements generally outnumber the microvertebrate remains of fishes and sharks; how widespread and common is this pattern, and what are the biological, ecological and taphonomic drivers? Does the higher abundance of conodonts really mean they were dominant components of Palaeozoic marine ecosystems?

New techniques applied to conodonts, many pioneered in Leicester (see Further Reading) have demonstrated that wear and 3D dental topographic analysis provide powerful insights into feeding mechanisms and dietary changes through time. This provides new ecological perspectives on the conodont fossil record and the ecosystems they were part of, but much remains to be done, including:

  • Assessing how the morphological details of complex P1 elements reflect trade-offs between adaptation to food processing and the constraints on occlusion;
  • Quantifying the degree of functional convergence between the teeth and claws of extant animals and cone-shaped conodont elements – which dominate the early part of the conodont fossil record – to elucidate their functional disparity, evolution, and ecological role in Early Palaeozoic ecosystems;
  • Applying similar approaches to understanding convergence and the biomechanics of conical feeding structures to fill the major gaps in our knowledge regarding the functional disparity of the conodont raptorial array of ‘ramiform’ elements, and its role of food acquisition.

Graphic showing six 3D digital elevation models of conodont element morphology and dental topographic analysis

Figure 1. 3D digital elevation models of conodont element morphology and dental topographic analysis (complexity, shown by the coloured patches with different orientations, increases left to right).

Host

University of Leicester

Theme

  • Organisms and Ecosystems

Supervisors

Project investigator

Mark Purnell, University of Leicester (mark.purnell[email protected])

Co-investigators

How to apply

Methodology

Quantitative approaches lie at the core of this project, so you should be keen to engage with quantification of 3D structure, and computational/mechanical and statistical methods of analysis. Although a series of well-constrained analyses lie at its core, this project also offers scope for an excellent student to develop the research in new directions.

Dietary and functional analysis will be based largely on 3D morphological data: analysis of dental topography (Pineda-Munoz 2017; Stockey et al. 2021; see Figure 1); further development of techniques developed by Murdock and Donoghue (Murdock et al. 2013); and the application to conodonts of new approaches to functional and dietary analysis of conical structures (Evans et al. 2021; Fischer et al. 2022).

Training and skills

Students will be awarded CENTA2 Training Credits (CTCs) for participation in CENTA2-provided and ‘free choice’ external training. One CTC equates to 1⁄2 day session and students must accrue 100 CTCs across the three years of their PhD.

In addition to standard micropalaeontological techniques, project specific training will include optical, Scanning Electron and 3D imaging; quantitative analysis of 3D complexity (using topographic and other metrics) and surface wear and damage. The emphasis will be on robust quantitative analysis and statistical hypothesis testing.

At Leicester, you will join the Centre for Palaeobiology and Biosphere Evolution – a well-equipped and dynamic group of researchers, PhD and Masters students who meet frequently to discuss their research. This includes other students working on novel analyses of diet and trophic niche in vertebrates.

This project is ideal for applicants with a first degree in geological or biological sciences and an aptitude for quantitative analysis.

Partners and collaboration

Professors Mark Purnell and Phil Donoghue have a long track record of innovative research in conodont palaeobiology and taphonomy. Purnell has expertise in the use of tooth wear and damage, and dental topographic analysis to infer diet and dietary change, while Donoghue has pioneered phylogenetic analysis of conodonts. Dr Duncan Murdock has developed new approaches to analysis of conodont function and established how they evolved from paraconodont ancestors. There are close links between respective research groups. The supervisors have collaborations and strong links into the international palaeontological community, and you will undertake data collection visits to overseas collaborators (e.g. USA, Europe and China).

Further details

Any questions? Contact Mark Purnell, University of Leicester, [email protected]

https://le.ac.uk/people/mark-purnell.

If you wish to apply to the project, applications should include:

  • A CV with the names of at least two referees (preferably three and who can comment on your academic abilities)

Applications to be received by the end of the day on Wednesday 11th January 2023. 

Possible timeline

Year 1

Formulate sampling strategy and acquire specimens for analysis in Leicester, including visits to overseas collections (USA, potentially China). Supplement existing data sets with 3D data and topographic analysis of conodonts and analogues, combined with analysis of functional morphology. Start data collection for analysis of damage and wear.

Year 2

Continued data collection. Publication of first results of functional and topographic analysis.

Year 3

Finish data collection; focus on analysis of evolutionary patterns and establishing the relationships with diet and trophic niche. Writing the thesis will take place during the final year, but papers will be published throughout the project. There will also be opportunties to give presentations at international meetings in the UK and overseas.

Further reading

Evans, A. R., T. I. Pollock, S. G. C. Cleuren, W. M. G. Parker, H. L. Richards, K. L. S. Garland, E. M. G. Fitzgerald, T. E. Wilson, D. P. Hocking & J. W. Adams 2021: A universal power law for modelling the growth and form of teeth, claws, horns, thorns, beaks, and shells. BMC Biol, 19, 58.

Fischer, V., R. F. Bennion, D. Foffa, J. A. MacLaren, M. R. McCurry, K. M. Melstrom & N. Bardet 2022: Ecological signal in the size and shape of marine amniote teeth. Proc Biol Sci, 289, 20221214.

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,

Pineda-Munoz, S., I. A. Lazagabaster, J. Alroy, A. R. Evans & N. Cooper 2017: Inferring diet from dental morphology in terrestrial mammals. Methods in Ecology and Evolution, 8, 481-491.

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.

Stockey, C., N. F. Adams, T. H. P. Harvey, P. C. J. Donoghue & M. A. Purnell 2022: Dietary inference from dental topographic analysis of feeding tools in diverse animals. Methods in Ecology and Evolution, 13, 1464–1474.

COVID-19

The University of Leicester has clear and effective guidelines and risk assessments that allowed for safe overseas data collection during the pandemic where it was essential for PhD research to progress. If prevailing conditions during this project prevent research visits to US collections, arrangements are in place for material to shipped to Leicester. Combined with the potential for major data collecting trips to be carried out in year 2 of the project, the impact of COVID-19 on the research can be mitigated.