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Hylke Bosma

H.F. (Hylke) Bosma, MSc., PhD candidate - Taxonomy and Systematics


Email: hylke.bosma@naturalis.nl
Phone: +31 (0)71-75 17 317
Room number: DW4.E01


My careerpath has not been a straight line, but more a winding road.

In 2003 I finished my Master's degree in Biology, specialisation palaeo-ecology at Utrecht University. After graduating I started working at the back office of the Veterinary Pathological Diagnostic Centre at Utrecht University. Since I still did not feel I had learned everything I could, I started the master's degree in Forensic Science at the Univeristy of Amsterdamin 2005. Upon finishing the degree, I have been involved in the MSc-programme as a teaching assistent and programme manager. 

In 2008 I transferred to Leiden University to work as the coordinator of the Graduate School of Science. In that position I mainly have been involved in the PhD programme of the faculty. I also focussed on management information and quality control of education in an academic environment.

Although my professional life has been focussed on educational management in an academic environment, I haven't lost my interest in fundamental research. In 2005 I started a project on the revision of a Cretaceous flora from the Netherlands. This project has been growing ever since and is now grown up to become a proper PhD project. Due to the fact that this project is carried out as a 'self-funded PhD candidate' and I still work at Leiden University, I spend about one day a week on doing research at Naturalis Biodiversity Center.


Research interest

During the Late Cretaceous (100,5 to 66 Ma) the angiosperms diversify and become the dominant contributor to the floras around the world. My interest goes out to the response of the conifers to this change in floristic composition. Comparison of different floras with diverse plant assemblages can give insight in evolutionary processes, responses to changes in climate and competition. Biogeographical and taphonomical factors are of importance too, to paint a complete picture of changes in diversity and dominance of the conifers.

Besides ecological interaction between (fossil) plants, nomenclatural issues have my interest too. Nomenclature is one of the most important ways to communicate between scientists about species, diversity and other concepts. Specifically fossil plants can pose a problem due to the fragmentary nature, isolated discoveries and long history of description.

Reviewing old literature, combined with new findings on different genera will provide more insight in the correct nomenclature. It will also make comparison between biogeographic regions and stratigraphically different location more easy when all specimens are correctly named and communicated about.


conifers, nomenclature, cretaceous, taphonomy, systematics, taxonomy

Current research topics

Late Cretaceous conifer floras of the Northern Hemisphere

PhD project under supervision of Prof.dr. J.H.A. van Konijnenburg-van Cittert

The Late Cretaceous can be characterised by a turnover from gymnosperm to angiosperm dominance. This change in diversity patterns of plants can be closely linked to the rise and radiation of the angiosperms. Gymnosperm diversity has been shown to increase up to the Aptian, followed by a progressive decline during the Late Cretaceous. The most widespread loss of gymnosperm diversity occurs during the mid-Cretaceous (Aptian to Cenomanian). In contrast to other gymnosperm groups, conifers are not greatly affected by this declines, as well as by the End-Cretaceous extinction. The diversity of conifers on a family level remains fairly constant throughout this event, where other gymnosperm orders, such as the Cycadales and Bennettitales, are significantly reduced or become extinct.

In the middle of the Late Cretaceous (Santonian) a flora dominated by conifer species has been recorded from South Limburg, The Netherlands. In most floras, conifers only make up a very small portion of flora, both in number of specimens found, and in the number of species described. A comprehensive review of the composition of floras throughout the Northern Hemisphere provides insight in the unique nature of this particular flora. 


Not applicable.



Not applicable.

Available student projects



Journals SCI, peer-reviewed

Bosma, H.F., van Konijnenburg-van Cittert, J.H.A. 2014. Revision of the Late Cretaceous conifer genus Moriconia. Palaeobiodiversity and Palaeoenvironments 94: 383-392.
Go to website (DOI)


Journals SCI, peer-reviewed

Bosma, H.F., Kunzmann, L., van Konijnenburg-van Cittert, J.H.A., Kvaček, J. 2012.Revision of the genus Cunninghamites (fossil conifers), with special reference to nomenclature, taxonomy and geological age. Review of Palaeobotany and Palynology 182: 20-31.
Go to website (DOI)


Journals SCI, peer-reviewed

Zijlstra, G.,  van Konijnenburg-van Cittert, J.H.A., Kunzmann, L., Bosma, H.F., Kvaček, J. 2010. (1925) Proposal to conserve the name Geinitzia with a conserved type (fossil Coniferophyta). Taxon 59: 301-302(2).
Go to website


Journals SCI, peer-reviewed

Bosma, H.F., van Konijnenburg-van Cittert, J.H.A., van der Ham, R.W.J.M., van Amerom, H.W.J., Hartkopf-Fröder, C. 2009. Conifers from the Santonian of Limburg, The Netherlands. Cretaceous Research 30: 483–495.
Go to website (DOI)