PeerJ Award Winner: Association Paléontologique Française (APF 2023)

The 2023 annual congress of the Association Paléontologique Française (APF) brought together the French paleontological community to the seaside city of Villers-sur-mer (Normandie) from the 5th to 9th of June. The congress was organized by the Paléospace museum. More than eighty researchers, postdoctoral academics, PhD students, students, and amateur palaeontologists discussed together during three days in a friendly atmosphere around oral communications and posters. From brachiopods to conifers, from amphibians to rudists, a wide range of topics were covered. The last day was dedicated to the field trip: walking on the shore to find Jurassic fossil! Some nice ammonites were discovered.

The winner of this year’s PeerJ Award is Romain Jattiot from the CR2P in Paris, for his excellent presentation on exceptionally well-preserved French heteromorph ammonites.

Bastien Mennecart (President of the APF)

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Romain Jattiot Centre de Recherche en Paléontologie, Paris” (CR2P), Sorbonne University, France

Can you tell us a bit about yourself and your research interests?

I am an invertebrate palaeontologist mainly focusing on the taxonomy, biostratigraphy, palaeobiology, and evolution of fossil mollusks (more specifically ammonoids). I have extensive field and laboratory skills and vast knowledge on the study of environment-biosphere interactions in context of crises. My long-term research goal is to better understand the ecological responses during periods of global change in the geological past. Indeed, only studies of biodiversity changes in deep time make it possible to completely unravel biodiversity crises and their precursory signs with high-resolution and can thus provide insights on the consequences of modern global change. To do so, the use of most recent advances in ammonoid taxonomy, robust quantitative biochronological methods, as well as global palaeobiodiversity analyses are the driving forces of my scientific career.

What first interested you in this field of research?

What first interested me in the field of paleontology is the unique opportunity to find in the field remains of organisms that lived millions of years ago. Nothing compares to the overwhelming feeling of being the first to lay eyes on a fossil that remained hidden in the rock for such a long time. Based on these fossils, I’m then very interested in understanding their evolutionary history and their palaeobiology, with a peculiar focus on ammonoids, which are fossil cephalopods related to the living squids, octopuses and cuttlefishes.

Can you briefly explain the research you presented at APF 2023?

In ammonites, the identification of mature shells is the logical but not naturally simple prerequisite to determine sexual dimorphism. In this research, we provide elements suggesting sexual dimorphism in the upper Albian Mariella bergeri species (Turrilitidae), based on three specimens with preserved adult peristome from the Clansayes locality (southeastern France). We compare the morphology of the terminal peristomes observed in M. bergeri with that of the few other known examples in Turrilitidae. In turn, we hypothesize that upper Albian Mariella (e.g., M. bergeri), lower Cenomanian Mariella (e.g., M. oehlerti) and lower Cenomanian Hypoturrilites (e.g., H. gravesianus) share the same peristome morphology. The observed similarities seem to support the close relationships between these three genera inferred from the most recent phylogeny of the family Turrilitidae. Conversely, the peristome morphology of upper Albian Turrilitoides appears markedly different. Finally, it is unclear how the shape of the adult peristome of upper Albian Ostlingoceras (e.g., O. puzosianum) and middle Cenomanian Turrilites (e.g., T. costatus) can be related to the evolutionary lineages among Turrilitidae. To further increase our knowledge on the differences in peristome morphologies among Turrilitidae, more complete and remarkably preserved specimens of various genera are needed.

How will you continue to build on this research?

I now plan to unravel the ontogeny, palaeobiology and phylogeny of the iconic ammonite genus Didymoceras (Ancyloceratina) from the US Western Interior (Late Cretaceous). As Mariella, Didymoceras is a genus of heteromorph ammonites. A large part of its shell morphology invites comparison with Mariella. However, all Didymoceras species are characterized by a very intricate ontogeny, with several profound morphological changes occurring throughout growth, all of which are subject to considerable intraspecific variability. To accurately describe the complete ontogeny of Didymoceras species, the considerable morphological intraspecific variability will be quantified in detail, based on modern and comprehensive biometric analyses.