Searching for the ORigin of the DINoflagellates in the Acritarch Representatives – ORDINAR
Searching for the ORigin of the DINoflagellates in the Acritarch Representatives
We will combine organic geochemistry, micro-infra-red spectroscopy, culturing and genetic techniques, and microscopic analyses (optical, TEM, SEM) to determine the biological affinities and the macromolecular characteristics of individual microfossils, including acritarchs and dinoflagellates. Our study should resolve - at least partly - the question about the origin of the dinoflagellates, and the biological affinity of the acritarchs.
Our study should resolve - at least partly - the question about the origin of the dinoflagellates, and the biological affinity of the acritarchs.
Our research project started in early 2023, and follows its original time frame. <br />A kick-off meeting organized as the first consortium meeting brought all partners together, in April 2023, at Lille University. This meeting was followed by a second consortium meeting organized, as planned, in March 2024 at Concarneau. <br />All milestone events originally scheduled took place, with the selection of modern and fossil dinocysts, and fossil acritarchs to be investigated (M2.1, M3.1., M4.1). The analyses of the ultrastructure of fossil dinocysts (Pleistocene-Holocene) is in progress as scheduled, in the frame of the studies of a Master student, Rahaf Ishokokani (M3.2.). However, although the initial phase of studying by microscopy the selected fossil acritarchs was started, the ultrastructural studies are delayed (no Master student recruited in 2024, and no sessions at SOLEIL planned) to 2025 (M4.2). Scientific dissemination started (M6.2), with first participation and presentations of our results at several international meetings (including, the International Palynological Congress, Prague, May 2024, the AASP, Montpellier, June 2024, and MedPalynoS, Salamanca, July 2024). Several publications are currently in progress (M6.4).<br />The main work load of WP4 (Paleozoic acritarchs) was originally planned to be in the frame of a PhD study, but this has been transformed into post-doctoral research, to be performed at Lille, with a recruitment in late 2024 or early 2025. <br />The post-doctoral research of WP2-3 (Dinocysts) started, as planned, in mid-2024, with the recruitment of Ophélie David (Univ. Brest). <br />The advancement of the research project is thus corresponding to the original time frame. The only exception is the work of the MSc student to be recruited in Lille in 2024; this work will be postponed to 2025.
Organic geochemistry, micro-infra-red spectroscopy, culturing and genetic techniques, and microscopic analyses (optical, TEM, SEM).
We are in the initial phase of the project.
A first publication announces future results:
Meyvisch, P., Mertens, K.N., Gurdebeke, P.R., Sandt, C., Pospelova, V., Vrielinck, H., Borondics, F., Louwye, S., 2023. Does dinocyst wall composition really reflect trophic affinity? New evidence from ATR micro-FTIR spectroscopy measurements. Journal of Phycology. DOI: 10.1111/jpy.13382
The dinoflagellates are one of the three major phytoplankton groups in modern oceans. They are known since the beginning of the Mezozoic (± 250 million years ago), but what is their origin? Several Proterozoic and in particular Palaeozoic acritarchs (± 540 to 250 million years ago) that are among the first signs of life are morphologically very similar to some modern dinoflagellate cysts. In addition, the stratigraphic, paleoecological and palaeogeographical distribution of these acritarchs is very similar to that of the modern dinoflagellates. However, it remains unclear if dinoflagellates are the organisms that produced these acritarchs. Microfossils of unequivocal dinoflagellate cyst morphology are not known until the Triassic, whereas organic biomarkers and physiology suggest a much older origin.? We therefore propose to compare the ancient acritarches with fossil and modern dinoflagellate cysts. Recently, it appeared that each modern dinoflagellate cyst species has a unique macro-molecular fingerprint. Here, we will use this information on an innovative way. We will combine organic geochemistry, micro-infra-red spectroscopy, culturing and genetic techniques, and microscopic analyses (optical, TEM, SEM) to determine the biological affinities and the macromolecular characteristics of individual microfossils, including acritarchs and dinoflagellates. Our study should resolve - at least partly - the question about the origin of the dinoflagellates, and the biological affinity of the acritarchs.
Project coordination
Thomas Servais (Université de Lille (EPE))
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Partnership
Université de Lille (EPE)
UBO-GeoOcean Université de Brest
SOLEIL Synchrotron SOLEIL
ODE-UL Institut Francais de Recherche pour l'Exploitation de la Mer
Help of the ANR 437,762 euros
Beginning and duration of the scientific project:
December 2022
- 48 Months
