Geier Christian

Christian Geier, BSc MSc

Scientific project collaborator (prae doc)
PhD Student
Ground floor, room 1
t: +43 (0)1 4277-540 00
m: christian.geier@univie.ac.at

Title of the Doctoral Thesis

Flower-insect interactions in the Eocene to Oligocene of Central Europe

Media contributions

Press release University of Vienna:
Bumble bees pollinated linden flowers already 24 million years ago – 22. September 2025

Research interests

Palynology
Ultrastructure of plants
X-Ray CT
Flower-insect interactions
pollination biology

Projects

Scientific project collaborator FWF-Project P 34303-B "Flower Power: can in-situ pollen link fossil plants to floral visitors?" (Friðgeir Grímsson)

Curriculum Vitae

Current position

2022– PhD student/Scientific project collaborator (prae doc) FWF-Project P 34303-B

Education and scientific career

2022– PhD Biology
2022 Master's Theses "The late middle Miocene palynoflora of Gratkorn, Styria, Austria"
2021 Student project collaborator FWF-Project P 29501-B25
2020–2022 Master's Programme Botany, University of Vienna
2016–2020 Bachelor's in biology with specialization in botany, University of Vienna (Thesis: Investigations to the distribution of Microthlaspi erraticum and Microthlaspi perfoliatum in eastern Austria using ITS based phylogeny)

Publications

2026

Ulrich, S., Purgina, C., Bouchal, J. M., Geier, C., & Grimsson, F. (2026). The use of transmission electron microscopy when investigating fossil angiosperm pollen: A review and suggestions for future applications. Review of Palaeobotany and Palynology, 344, Article 105423. https://doi.org/10.1016/j.revpalbo.2025.105423

2025

Geier, C., Engel, M. S., Bouchal, J. M., Ulrich, S., Schönenberger, J., Uhl, D., Wappler, T., Wedmann, S., Boudet, L., & Grimsson, F. (2025). 24 million years of pollination interaction between European linden flowers and bumble bees. New Phytologist, 248(4), 2111-2127. https://doi.org/10.1111/nph.70531

Pan, A. D., Jacobs, B. F., Currano, E. D., Gostel, M. R., Lowry, II, P. P., Plunkett, G. M., Hoffmann, J., Geier, C., & Grimsson, F. (2025). Fossil Astropanax Seem. (Araliaceae) from the early Miocene (21.73 Mya) Mush Valley plant assemblages of Ethiopia. Botanical Journal of the Linnean Society, 209(3), 280-302. Article boaf011. https://doi.org/10.1093/botlinnean/boaf011

Bouchal, J. M., Geier, C., Ulrich, S., Wilde, V., Lenz, O. K., Zetter, R., & Grimsson, F. (2025). Qualitative LM and SEM study of the Messel palynoflora: Part II. Fabales to Caryophyllales. Review of Palaeobotany and Palynology, 341, Article 105349. https://doi.org/10.1016/j.revpalbo.2025.105349

Geier, C., Ulrich, S., Bouchal, J. M., Zetter, R., Ngô Muller, V., Jacobs, B. F., Uhl, D., & Grimsson, F. (2025). Morphology and ultrastructure of Tilioideae pollen: how to differentiate Craigia, Mortoniodendron, and Tilia. Botanical studies, 66(1), Article 15. https://doi.org/10.1186/s40529-025-00463-1

Geier, C., Bouchal, J. M., Ulrich, S., & Grimsson, F. (2025). Identifying Tilioideae pollen in the fossil record using electron microscopy. In Abstract EGU25 Article EGU25-17212 https://doi.org/10.5194/egusphere-egu25-17212

Boudet, L., Geier, C., Engel, M. S., Grimsson, F., Bouchal, J. M., Ulrich, S., & Wedmann, S. (2025). Majesties among the insects - new crown wasps (Hymenoptera: Stephanidae) from the Eocene Messel Pit. In S. Wedmann, & K. T. Smith (Eds.), The World at the Time of Messel. Back to the Future?: International Senckenberg Conference. Conference Volume (pp. 27). Senckenberg-Ges. für Naturforschung.

Geier, C., Bouchal, J. M., Boudet, L., Uhl, D., Engel, M. S., Nel, A., Ngo-Muller, V., Schönenberger, J., Ulrich, S., Wappler, T., Wedmann, S., & Grimsson, F. (2025). Paleo-pollination by Hymenoptera in the paleogene of Europe. In S. Wedmann, & K. T. Smith (Eds.), The World at the Time of Messel. Back to the Future?: International Senckenberg Conference. Conference Volume (pp. 38). Senckenberg-Ges. für Naturforschung.

Boudet, L., Geier, C., Grimsson, F., Bouchal, J. M., Ulrich, S., Wappler, T., & Wedmann, S. (2025). Scoliid wasps from the eocene of Messel: pollinivory and pollination. In S. Wedmann, & K. T. Smith (Eds.), The World at the Time of Messel. Back to the Future?: International Senckenberg Conference. Conference Volume (pp. 26). Senckenberg-Ges. für Naturforschung.

2024

Grimsson, F., Geier, C., Bouchal, J. M., Ulrich, S., Zetter, R., & Vieira, M. (2024). Fossil Hyaenanche Pollen from the Eocene of Kenya: The Paleophytogeograpy and Paleoclimate of a Relict Plant Genus Endemic to the Cape Province, South Africa. Biology, 13(12), Article 1079. https://doi.org/10.3390/biology13121079

Wuttke, M., Poschmann, M. J., Wappler, T., Bouchal, J. M., Geier, C., Ulrich, S., & Grimsson, F. (2024). Pollen-feeding in a giant pelobatid tadpole from the late Oligocene of Enspel, Germany. Palaeobiodiversity and Palaeoenvironments, 104(4), 999-1026. Article 104831. https://doi.org/10.1007/s12549-024-00603-8

Geier, C., Engel, M. S., Bouchal, J. M., Ulrich, S., Grimsson, F., Wedmann, S., & Wappler, T. (2024). The earliest large carpenter bee (Xylocopa) and its adhering pollen (Araliaceae, Theaceae). Palaeobiodiversity and Palaeoenvironments, 104(4), 949-962. Article s12549-024-00604-7. https://doi.org/10.1007/s12549-024-00604-7

Geier, C., Bouchal, J. M., Ulrich, S., Uhl, D., Wappler, T., Wedmann, S., Zetter, R., Schönenberger, J., & Grimsson, F. (2024). Potential pollinators and paleoecological aspects of Eocene Ludwigia (Onagraceae) from Eckfeld, Germany. Palaeoworld, 33(4), 1079-1104. https://doi.org/10.1016/j.palwor.2023.07.003

Auer, W., Geier, C., Bouchal, J. M., & Grimsson, F. (2024). Tilia americana. Web publication https://www.paldat.org/pub/Tilia_americana/306663

Ulrich, S., Vieira, M., Coiro, M., Bouchal, J. M., Geier, C., Jacobs, B. F., Currano, E. D., Lenz, O. K., Wilde, V., Zetter, R., & Grimsson, F. (2024). Origin and Early Evolution of Hydrocharitaceae and the Ancestral Role of Stratiotes. Plants, 13(7), Article 1008. https://doi.org/10.3390/plants13071008

Geier, C., Bouchal, J. M., & Grimsson, F. (2024). Tilia chinensis. Web publication https://www.paldat.org/pub/Tilia_chinensis/306674

Halbritter, H., Heigl, H., Auer, W., Gastaldi, C., Geier, C., Bouchal, J. M., & Grimsson, F. (2024). Tilia cordata. Web publication https://www.paldat.org/pub/Tilia_cordata/306671

Geier, C., Bouchal, J. M., & Grimsson, F. (2024). Tilia endochrysea. Web publication https://www.paldat.org/pub/Tilia_endochrysea/306676

Geier, C., Bouchal, J. M., & Grimsson, F. (2024). Tilia miqueliana. Web publication https://www.paldat.org/pub/Tilia_miqueliana/306675

Geier, C., Bouchal, J. M., & Grimsson, F. (2024). Tilia mongolica. Web publication https://www.paldat.org/pub/Tilia_mongolica/306670

Geier, C. (2022) The late middle Miocene palynoflora of Gratkorn, Styria, Austria. University of Vienna (Masterthesis)

Geier, C. (2020) Investigations to the distribution of Microthlaspi erraticum and Microthlaspi perfoliatum in eastern Austria using ITS based phylogeny. University of Vienna (Bachelorthesis)