PhD thesis in Paleontology - Combined contributions from imaging techniques and new fossils to the understanding of marine ecosystem dynamics after the Permian–Triassic crisis (M/F))

Job Description

Thesis Subject

PhD title: Combined contributions from imaging techniques and new fossils to the understanding of marine ecosystem dynamics after the Permian–Triassic crisis

In what environmental settings can biodiversity recover after massive extinction events? To address this major question, we study the aftermath of the Permian/Triassic mass extinction (~252 Myr). The subsequent biotic recovery is assumed to have been significantly delayed. It also marks the expansion of the Modern Evolutionary Fauna, which led to present-day marine ecosystems. Research conducted by our team in the western USA basin suggests that complex marine ecosystems – including the Paris Biota – likely persisted for part of the Early Triassic, at a time and place supposedly depauperate. These findings also show that the Early Triassic fossil record remains incompletely known, likely resulting from marked preservation and sampling biases. The newly discovered fossil assemblages, which have yet to be fully explored and studied, constitute the core of this PhD project. They raise numerous key questions regarding the actual composition, duration and environmental setting of these ecosystems. Especially, these new data indicate that the Early Triassic fossil record is far from being completely known and that complex marine ecosystems likely appeared as early as the Smithian. The PhD objectives are to (i) determine the still enigmatic fossil contents of these deposits, (ii) investigate the taphonomic and environmental conditions that favored or hindered their development and/or made them visible in the fossil record, and (iii) explore and then apply various innovative imaging techniques (photoluminescence, X-rays, etc.) to investigate points (i) and (ii).
One of the major contributions of this PhD will be the high-resolution analysis of these post-crisis ecosystems and their associated paleoenvironments through a characterization of the quality of their fossil record and an assessment of the still poorly-known diversity within contemporary assemblages. In addition, new imaging techniques may be tested on fossil or modern specimens from other localities in order to evaluate their analytical potential in paleontology. This exploration will enable us to address, for example, the preservation of colored patterns and the identification of hidden anatomical features.

Given the multidisciplinary nature of this PhD, the candidate will carry out a wide range of paleontological analyses, integrating innovative imaging techniques. The candidate will help to strengthen the interdisciplinary approach of an ANR project involving palaeontologists and experts in imagery, sedimentology and macroecology. A strong background in natural sciences and/or in imaging will be appreciated. The successful candidate should have a good knowledge of one or more techniques relevant to the project (taxonomy – optical, electronic and chemical imaging) and should have completed a Master's degree in Paleontology, Geosciences or Materials Science. He/she should show curiosity for paleontological issues and a strong interest in experimental and exploratory work. The candidate should enjoy working both independently and in a highly interdisciplinary collaborative environment. Good communication skills and a written and spoken understanding of English are required for the dissemination of results to the international scientific audience in the relevant fields.
A Master's degree with honours is a prerequisite (It can be obtained until the end of June 2026). The priority areas of the project may be adapted to some extent according to the skills of the successful candidate.

Your Work Environment

Funding is provided by the ANR PT-Revival project, led by A. Brayard and involving a consortium of five laboratories: Biogéosciences (Dijon), LEHNA (Lyon), LMV (Clermont-Ferrand), PPSM and IPANEMA (Paris-Saclay).
The PhD will be supervised by Arnaud Brayard (CNRS Research Director) and Emmanuel Fara (Professor, UBE) and will be carried out at the Biogéosciences laboratory (CNRS/Université Bourgogne Europe; https://biogeosciences.u-bourgogne.fr) in Dijon. The project will benefit from both the facilities available at Biogéosciences (GISMO geochemical analysis and imaging platform, preparation rooms and palaeontological collections, photoluminescence technical platform, etc.) and those available in the other laboratories of the consortium (photoluminescence and Raman platforms, computing equipment, synchrotron expertise, microscopy platforms at the University Paris-Saclay).

Recent publications describing the scientific context are available at the following address: http://arnaudbrayard.wordpress.com/

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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