2025-B28 Making sense of early vertebrates

Project highlights

Opportunity to join a world-leading team working on the evolution of early vertebrates

Learn cutting-edge imaging techniques and developing innovative interpretive skills

Development of 3-dimensional models of early vertebrate heads

Overview

The acquisition of a head and its associated sense organs by vertebrates over 500 Ma (million years ago) was one of the major transitions in animal evolution, and is thought to have contributed to the dominance of vertebrates in modern-day ecosystems. This precaudal head’s sense organs include structures for sensing light (eyes/pineal), chemicals (nose), orientation (inner ear), and pressure and vibration (sensory lines). In living vertebrates the development and anatomy of these sense organs is complex and reflects a vast span of phylogenetic, developmental and ecophenotypic evolution. This means that living vertebrates offer a diverse array of placements of sense organs that are somewhat divorced from their origins.

The Palaeozoic fossil record of early skeletonising vertebrates provide a potential cipher by revealing cranial organisation at an early point in time close to the origin of the ‘new head’. Within the ‘ostracoderms’, a loosely defined group of jawless fish that dominate the vertebrate fossil record from the middle Ordovician to the end of the Devonian (approximately 470 to 360 Ma), sensory structures and the brain create distinctive hard tissue signatures that permit their identification in fossil specimens. Using high resolution 3d datasets, the project will look to build schematic models for the distribution of these structures with an aim to reconstruct the ancestral states (e.g. eyes anterior, lateral or dorsal, pineal paired or single) across early vertebrates and assess the evolution of vertebrate sense organs over time. 

Figure 1 A) Phylogeny of ‘ostracoderms’, B- E CT rendered head of a heterostracan in B) left lateral view C) ventral view of dorsal headshield D) medial slice through head and E) posterior view through head Colour key for B-E yellow = pineal, red = openings for sensory canals, purple = eyes, green = semi-circular canals, buff = gill pouches .

Host

University of Birmingham

Theme

Organisms and Ecosystems

Supervisors

Project investigator

Ivan Sansom University of Birmingham ([email protected])

Co-investigators

Sam Giles University of Birmingham ([email protected])
Richard Dearden, Naturalis Biodiversity Center, Leiden ([email protected])
Martin Brazeau, Imperial College, London ([email protected])

How to apply

Each host has a slightly different application process.
Find out how to apply for this studentship.
All applications must include the CENTA application form.
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Methodology

Non-destructive three-dimensional imaging methods such as X-ray computed tomography (CT) and synchrotron X-ray microtomography will provide the basis for the project, enabling the visualization of these structures in ostracoderms. After reconstruction, the student will investigate and evaluate interpretations of the sensory structures and develop idealized models of their morphology and arrangement. These results will elucidate the range and relative placement of sensory structures within early vertebrates within the context of their evolutionary history. 

Training and skills

DRs will be awarded CENTA Training Credits (CTCs) for participation in CENTA-provided and ‘free choice’ external training. One CTC can be earned per 3 hours training, and DRs must accrue 100 CTCs across the three and a half years of their PhD.

The student will gain a wide variety of experience and training in imaging techniques (principally microCT scanning) and reconstruction and visualisation of digital 3D datasets (focussing on the hard tissue anatomy of the heads of selected fossil specimens) and their interpretation. There will be opportunities for research visits to museums within Eur

Partners and collaboration

Richard Dearden (Naturalis) and Martin Brazeau (Imperial College) will contribute to the overall project development. Both have extensive experience in the study of early vertebrates and will provided experience in dealing with some of the taxonomic groups and datasets that will form part of this study.

Further details

Prospective applicants are positively encouraged to contact Ivan Sansom ([email protected]) in advance of applying to ask questions about the project, discuss whether working with us on this project at the University of Birmingham is a good fit for you, or to ask questions about putting together a strong application. We are also happy to put you in contact with current and former students to ask questions about their experiences.

 To apply to this project: 

You must include a CENTA studentship application form, downloadable from: CENTA Studentship Application Form 2025.

You must include a CV with the names of at least two referees (preferably three) who can comment on your academic abilities.

Please submit your application and complete the host institution application process via: https://sits.bham.ac.uk/lpages/LES068.htm.   Please select the PhD Geography and Environmental Science (CENTA) 2025/26 Apply Now button. The CENTA Studentship Application Form 2025 and CV can be uploaded to the Application Information section of the online form.  Please quote CENTA 2025-B28 when completing the application form.

 Applications must be submitted by 23:59 GMT on Wednesday 8th January 2025.  

Possible timeline

Year 1

Identifying suitable specimens for tomographic study (these will include data sets already acquired by the supervisorial team as well as museum visits to study specimens first hand). Training in data acquisition and interpretation.

Year 2

Building digital reconstructions of the hard tissues of the ostracoderm heads and development of landmarking models of the placement of their sense organs.

Year 3

Interpretation of data sets in phylogenetic and palaeoenvironmental contexts and writing up of thesis.