Overview

Project Highlights:

  • Analyse major evolutionary drivers (before, during and after major perturbations in the biosphere) using the exceptionally good fossil record of conodonts
  • Use cutting edge approaches to analysis of shape, function and diet to interpret the conodont fossil record in terms of the differential evolutionary success and survival of ecological guilds
  • Opportunities to travel to collect data from fossil collections (e.g. China, USA).

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.

Pioneering work at Leicester (Purnell 1995; Purnell and Jones 2012) is demonstrating 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; Puneda-Munoz et al. 2016) can be applied to conodonts, providing an additional, independent test of trophic ecology (Figure 1).

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.

This project is ideal for applicants with a first degree in geological or biological sciences and an aptitude for quantitative analysis. At Leicester you will join a dynamic group of researchers, PhD and Masters students working on novel analyses of diet and trophic niche in fossil vertebrates.

Figure 1. 3D digital elevation models of conodont element morphology and surface orientations used for OPC (orientation patch count) measures of complexity (complexity increases left to right).

Methodology

Evolutionary patterns will be investigated quantitatively using both phylogenetic and stratigraphic range data. Dietary analysis will be based on quantitative analysis of surface damage and wear using approaches developed by Purnell and Jones (2012), and analysis of complexity using orientation patch count (OPC) and other methods (Puneda-Munoz et al. 2016; Evans et al. 2007; see Figure 1) applied to high resolution 3D morphological data. The project will also develop new methods of analysis of tooth function in non-platform elements, based on techniques recently developed by Murdock and Donoghue (Murdock et al. 2013). New approaches to taphonomic analysis of postmortem wear in conodont elements (pre- and post-burial) will be developed.

Training and Skills

CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to the student's projects and themes. 

In addition to standard micropalaeontological techniques, project specific training will include optical, Scanning Electron, and focus variation microscopy, both 2D and 3D; quantitative analysis of 3D complexity (using OPC and other measures) and surface wear and damage; techniques for phylogenetic testing and analysis of macroevolutionary patterns. The emphasis will be on analysis of evolutionary and ecological patterns through robust quantitative approaches and statistical hypothesis testing.

Timeline

Year 1. Formulate sampling strategy and acquire specimens for analysis in Leicester, including visits to overseas collections (China and USA). Supplement existing proof of concept data sets with 3D data and OPC analysis of conodonts and analogues. Develop generic level database of conodont diversity through time. Start data collection for analysis of damage and wear.

Year 2. Continued data collection. Analysis (OPC and other proxies) of relationship between morphological complexity and diet in non-mammalian teeth (to publication; will also be a thesis chapter).

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.

Partners and collaboration (including CASE)

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 to infer dietary change in extinct organisms, 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

Enquiries to Mark Purnell, University of Leicester, mark.purnell@le.ac.uk.