PhD in Palaeoecology: How Did Palaeozoic Marine Food Webs Change as Vertebrate Predators Emerged?

PhD in Palaeoecology: How Did Palaeozoic Marine Food Webs Change as Vertebrate Predators Emerged?

Quick Decision

Strong but verify fit. YES-27-E-02 is a clearly framed, ambitious macroecology PhD at Leeds. It tests whether vertebrate predators reorganized Paleozoic marine food webs or whether the proposed Devonian “nekton revolution” was one phase of a slower, multi-driver transition. The work connects fossil-occurrence and diversification analysis, food-web reconstruction, and functional morphology. It fits applicants interested in ecology, evolutionary biology, palaeobiology, or quantitative Earth science; R is advantageous, not essential. The strongest features are the explicit cross-scale methods and links to DeepBio@Leeds and Leeds palaeobiology. Before applying, clarify the conflicting opening dates, the 2027/28 stipend and written international-fee coverage; also confirm Cassius Morrison’s role in the Leeds co-supervision team. The deadline is 12 January 2027 at 13:00 GMT. Project page · Apply page · How to apply

Research Problem and Doctoral Work

What Is Unsolved and Why It Matters

Silurian and Devonian seas saw jawless vertebrate diversification, the evolution of jaws and teeth, and radiation among placoderms, chondrichthyans, and early bony fishes. A long-standing interpretation casts this as a Devonian nekton revolution: active swimmers expanded into the water column and changed marine food webs. Yet large predators already existed. Orthocone cephalopods and eurypterids held apex roles before vertebrates rose. The important question is whether vertebrates replaced incumbent consumers or brought new feeding strategies, predator traits, and connections between pelagic and benthic communities.

The project's macroecological importance lies in testing how evolutionary innovations affect ecosystem architecture across geological time. It also places the question alongside the Great Ordovician Biodiversification Event and Mesozoic Marine Revolution. The project allows for a discrete Devonian transition or longer Paleozoic restructuring. Existing studies do not settle the issue: the 2010 formulation of the Devonian revolution provides a hypothesis, while a 2018 occurrence analysis finds nekton important earlier and no simple increase through the Devonian. A 2025 study adds ocean oxygenation as a possible contributor to deeper-water expansion. These are reasons for careful comparative work, not signs that the question lacks value. Project description · Klug et al. 2010 · Whalen and Briggs 2018 · Oxygenation study, 2025

Work, Methods, and Potential Outputs

The official plan has three connected workstreams:

1. Diversification and turnover. Compile Silurian–Carboniferous vertebrate occurrences from published literature and the Paleobiology Database, alongside major predator and prey guilds. Compare diversity, origination/extinction, sampling-standardized patterns, predator turnover, possible prey defenses, and vulnerable benthic-community change.
2. Food-web reconstruction. Build marine networks in time slices from the Late Ordovician to Carboniferous. Infer feeding links from functional traits, body size, feeding morphology, phylogenetic constraints, sedimentology, and palaeoenvironmental data. Listed measures include connectance, generality, vulnerability, motif distributions, mean trophic level, and food-chain length. The tests concern trophic complexity, benthic–pelagic integration, new feeding guilds, and abrupt versus gradual change.
3. Functional evolution. Assemble jaw and tooth architecture, cranial mechanics, body size, locomotion, limb morphology, and dental microwear. Candidate methods include functional disparity, morphospace, ecological-guild reconstruction, dental microwear texture analysis (DMTA), functional-trait analysis, and geometric morphometrics.

These methods appear in the project outline, but it does not state that each is mandatory or how time will be divided among strands. It also does not specify which datasets, specimens, or collections are already assembled. Preserve integration while agreeing a tractable primary question and staged milestones.

Causal inference is the main scientific boundary. Fossil occurrences are uneven, preservation is selective, and many reconstructed food-web links are inferred. Bite marks can provide more direct interaction evidence, but are sparse and taxonomically uneven. Exceptional Devonian assemblages can constrain trophic models through digestive contents, bite marks, ecomorphology, and co-occurrence, but do not remove uncertainty at broader timescales. Network metrics should be tested against sampling, preservation, and alternatives such as oxygenation and nutrient supply. The project explicitly notes incumbent invertebrate predators, giving it a stronger causal framing than a simple “fish caused the change” narrative. Bite-mark study · Devonian fish food-web study · Trait-based food-web framework, preprint

Potential contribution: a comparative, uncertainty-aware account of when vertebrate predation expanded, whether functional roles changed beyond taxonomic diversity, and how predator/prey guilds relate to network structure. These are research aims, not guaranteed findings or publications.

School, Programme and Field Context

The official host is the University of Leeds School of Earth, Environment and Sustainability, and the project is situated in DeepBio@Leeds. Leeds is the application route and likely registration location, but confirm the formal degree-awarding body in the offer. Academic co-supervisors are named at Leeds, Sheffield, and Bristol; the project page says it is not a CASE/collaborative project. Multi-university supervision does not establish a joint degree. Project page

DeepBio@Leeds focuses on large-scale macroevolutionary and macroecological processes through deep time. CASCaDE combines fossil datasets and ecological modelling around food webs and ecosystem resilience. Palaeo@Leeds is an interdisciplinary cluster. These pages support topical fit but do not specify this student's data/software allocation, collections access, group size, or supervision cadence. Ask what support is available for occurrence databases, network methods, R, morphometrics, and specimen work. DeepBio@Leeds · CASCaDE · Palaeo@Leeds

Leeds reports that 96% of activity in REF 2021 Earth Systems and Environmental Sciences UoA7 was judged world-leading or internationally excellent. This is a broad research-assessment result, not a palaeontology ranking or a measure of this project or supervisor. Confirm the 2027 cohort training schedule and formal registration terms. Leeds REF summary · Official REF UoA7 results · University of Leeds

Supervisor and Lab Assessment

Supervisor Research Directions

Professor Alex Dunhill's official profile identifies expertise in palaeobiology, palaeoecology, quantitative palaeontology, macroevolution, macroecology, biogeography, and mass extinctions. He directs the Earth Surface Science Institute and is part of Palaeo@Leeds. This, together with DeepBio and CASCaDE, fits the project's integration of fossil records, ecological networks, and deep-time change. Alex Dunhill profile

The project lists Andrew Beckerman (Sheffield Biosciences), Cassius Morrison (Leeds Earth Environment), Joe Keating (Bristol Life Sciences), and Paul Wignall (Leeds) as academic supervisors. Their participation indicates a wider quantitative ecology and palaeontology network, but the page does not define each person's role. A current-affiliation question remains: 2026 UCL news places Dr Cassius Morrison in UCL Earth Sciences/Natural History Museum collaboration, whereas this project lists him at Leeds. Resolve this directly; the discrepancy alone does not prove that the project page or role is incorrect. Project page · UCL 2026 research news

Recent Important Publications

Work	Contribution and relevance	Caveat
Dunhill et al. (2024), Extinction cascades, community collapse, and recovery across a Mesozoic hyperthermal event	Uses time-sliced fossil food webs to study collapse and recovery; close methodological connection to proposed network work.	Different interval/event; does not demonstrate the Devonian hypothesis.
Clay et al. (2024), Trait Networks: Quantifying Marine Community Resilience and Extinction Recovery	Applies trait-network measures to marine resilience and recovery, linking functional traits with community patterns.	Trait networks are not trophic interaction networks; trait choice and coverage affect interpretation.
Morrison et al. (2025), Rise of the king: Gondwanan origins and evolution of megaraptoran dinosaurs	Shows recent comparative anatomy, phylogenetic, and biogeographic fossil analysis by a named co-supervisor.	Different taxon and period; verify Morrison's project role.
Morrison et al. (2026), Inter- and intraspecific variation in theropod dinosaur dental microwear and its palaeoecological implications	Method-adjacent work relevant to DMTA and feeding ecology.	Different taxon and period; microwear depends on preservation and sampling.

These papers show complementary expertise rather than direct replication of the proposed Devonian fish study. Confirm who oversees network analysis, fossil morphology, and integration. Dunhill et al. 2024 · Clay et al. 2024 · Morrison et al. 2025 · Morrison et al. 2026

Lab, Resources, and Collaboration Environment

DeepBio and CASCaDE provide the clearest documented topical fit. Their public pages show macroecology and network-based fossil ecosystem research; they do not promise dedicated equipment, collections access, or particular software support. The proposal is mainly analytical, though morphology may require specimen/image access. Ask how those records are sourced and quality-controlled, whether collection visits are funded, and what quantitative training is available. DeepBio projects · CASCaDE

Funding, Application, and Living Cost

YES-DTN describes a full studentship of 3.5 years with a stipend at UKRI rates, university fees, and support for research, fieldwork, training, and conference travel. Programme guidance describes an optional three-month placement that may extend the studentship to 3.75 years, but availability for this non-CASE project is unconfirmed; do not assume it is offered. The FAQ explicitly says all university tuition is covered regardless of home/international fee difference. It also says up to 30% of full awards may go to international applicants; full fee-gap language therefore does not remove competition for funded places. Visa, Immigration Health Surcharge and relocation are excluded under the programme guidance. Budget for routine housing from the stipend; confirm in writing the reimbursement boundary between approved research, fieldwork and conference travel or accommodation and personal travel costs. Ask whether the written award covers full international-rate tuition in every funded year and whether a bench fee applies. YES-DTN FAQ · Leeds postgraduate fees

UKRI's published 2026/27 minimum stipend is £21,805; the October 2027 rate is unconfirmed. Leeds' 2026 guide gives an average of £320 per week, or £16,640 for 52 weeks. The simple difference is £5,165 before personal variation, inflation, travel, deposits/setup, visa and IHS. This suggests a plausible but not generous margin, not guaranteed savings. Recalculate using 2027 housing and the actual stipend. UKRI guidance · Leeds living expenses

The closing deadline is 12 January 2027 at 13:00 GMT. The Apply page says forms open 2 November 2026, while the detailed How to Apply page says 12 November at 10:00 GMT. Confirm which opening date applies and follow the application instructions for both forms. Both a Leeds online application and separate YES-DTN form are required; Leeds issues the student ID needed on the network form. Only one network application is accepted, with an optional second choice from the same school. Use code YES-27-E-02 exactly; instructions warn that code errors cannot be manually corrected. Apply page · How to Apply

Applicant Fit and Preparation

Required Background and Skills

The project lists ecology, palaeobiology, evolution, physical/biological sciences, or mathematics as relevant backgrounds. The general network minimum is a relevant 2:1 or equivalent; a first is usually more competitive for funding, while a strong relevant master's can help some applicants with a 2:2. R is advantageous but not essential. The FAQ says prior publications are not required and transferable skills may support a field change. Confirm English-language thresholds and equivalencies for your country. Project page · YES-DTN FAQ

Preferred Experience and Suggested Preparation

The formal project description treats R as advantageous rather than required. As preparation, build a small reproducible analysis in R or an equivalent language and practice documenting occurrence-data cleaning, taxonomic uncertainty, time bins, sampling-standardization assumptions, and missingness. Read both the original revolution hypothesis and later challenges, then propose a test distinguishing predator escalation from environmental change. Applicants with morphology experience can show how measurements link to ecological function; ecology or mathematics applicants can show comfort with biological and fossil evidence. Use one or two concrete examples instead of claiming mastery of every method.

Potential routes include postdoctoral and academic research, museum collections and curation, education/outreach, and adjacent quantitative biodiversity or environmental analysis. Permanent academic and museum jobs are competitive. Coding, statistics, data stewardship, collaboration and communication are portable strengths; the PhD cannot guarantee a particular role. Prospects career profile · National Careers Service profile

Next Actions and Questions to Verify

Before Applying

• Ask the network which opening date applies; the stated closing time is consistent.
• Confirm code, second-choice rules, statement format, and English-language evidence timeline.
• Ask the primary supervisor which workstream is primary, what data are ready, and whether R or fossil-taxonomy skills are expected at entry.
• Clarify whether Cassius Morrison currently holds the listed role and how Leeds, Sheffield, and Bristol divide supervision.
• Obtain written confirmation of full international-rate tuition for all funded years and any bench fee.

At Interview

• Ask how analyses handle sampling, preservation, taxonomic uncertainty, and inferred trophic links.
• Ask how the design distinguishes predation from oxygenation, nutrient supply, plankton change, and broader faunal turnover.
• Request first-year milestones, quantitative-method training, access to collections/images, and realistic scope.
• Clarify research/fieldwork/conference funds and whether placement is optional or competitive.

Before Accepting an Offer

• Check degree-awarding institution, international fee classification, stipend by year, duration, bench fees and placement terms.
• Recalculate living costs with 2027 housing; separately budget visa, IHS, travel and setup.
• Confirm supervision cadence, data access, milestones and publication expectations.

Evidence and Sources

Project, application, funding, and costs

• YES-27-E-02 official project page
• YES-DTN Apply
• YES-DTN How to Apply
• YES-DTN FAQs
• UKRI studentship guidance
• Leeds living-cost guide
• Leeds PGR fees
• University of Leeds

School, group, and supervisor

• Leeds REF 2021 summary
• Official REF UoA7 profile
• DeepBio@Leeds
• DeepBio projects
• Palaeo@Leeds
• Alex Dunhill profile
• CASCaDE
• UCL 2026 news on Cassius Morrison

Publications, field context, careers

• Dunhill et al. 2024
• Clay et al. 2024
• Shaw et al. food-web framework preprint
• Klug et al. 2010
• Whalen and Briggs 2018
• Mid-Devonian oxygenation study
• Bite marks and fossil predation
• Devonian fish food-web study
• Morrison et al. 2025
• Morrison et al. 2026 microwear study
• Prospects palaeontologist profile
• National Careers Service profile