Taxonomy and nomenclature in palaeopalynology: basic principles, current challenges and future perspectives

Abstract

Effective communication of taxonomic concepts is crucial to meaningful application in all biological sciences, and thus the development and following of best practices in taxonomy and the formulation of clear and practical rules of nomenclature underpin a wide range of scientific studies. The International Code of Nomenclature for algae, fungi and plants (the Code), currently the Shenzhen Code of 2018, provides these rules. Although early versions of the Code were designed mainly with extant plants in mind, the Code has been increasingly used for fossil plants and, in recent decades, for organic-walled microfossils, the study of which is called palaeopalynology, or simply palynology. However, rules embodied in the Code do not fully reflect the needs and practices of this discipline; and taxonomic practices between fossil applications, especially in palynology, have tended to diverge from practices for extant plants. Differences in these rules and practices present specific challenges. We therefore review the Shenzhen Code as it applies to palynology, clarifying procedures and recommending approaches based on best practices, for example, in the designation and use of nomenclatural types. The application of nomenclatural types leads to taxonomic stability and precise communication, and lost or degraded types are therefore problematic because they remove the basis for understanding a taxon. Such problems are addressed using examples from the older European literature in which type specimens are missing or degraded. A review of the three most important conventions for presenting palynological taxonomic information, synonymies, diagnoses/descriptions and illustrations, concludes with recommendations of best practices. Palynology continues to play an important role in biostratigraphy, palaeoenvironmental analyses, and evolutionary studies, and is contributing increasingly to our understanding of past climates and ocean systems. To contribute with full potential to such applied studies, consistent communication of taxonomic concepts, founded upon clear rules of nomenclature, is essential.

Keywords:

• Shenzhen Code
• synonymy
• types
• typification
• curation
• diagnosis
• best practice

Acknowledgements

Our sincere thanks go to the institutions and collections staff who provided access to collections, samples and permission to print images: Museum für Naturkunde Berlin – Melanie Diebert, Cornelia Hiller, Catrin Puffert; Federal Institute for Geosciences and Natural Resources in Hannover and Spandau – Angela Ehling, Carmen Heunisch, Annette Götz; and the Geological Survey of Austria – Regine Zorn. JG thanks also Wolfram Kürschner (University of Oslo, Norway), who organised the visit to the Geological Survey of Austria, which brought her for the first time in contact with type material and associated challenges discussed in this paper. We thank Thomas Borsch and members of the technical staff: Bettina Giesicke, Kim Govers, Sabine Scheel of the Botanic Garden and Museum Berlin, Freie Universität Berlin, for access and service of the microscope. Martin J. Head acknowledges support from a Natural Sciences and Engineering Research Council of Canada Discovery Grant. James B. Riding publishes with the approval of the Executive Director, British Geological Survey (NERC). Robert A. Fensome acknowledges support of the Geological Survey of Canada (GSC), Natural Resources Canada: this is NRCan Contribution number 20210005. We thank Natalia Zavialova (Paleontological Institute Moscow) and an anonymous reviewer, as well as GSC internal reviewer Manuel Bringué, for their constructive feedback and ideas which greatly improved this manuscript. Permission to reproduce images used in Figure 6 was kindly granted by Schweizerbart Science Publishers (www.schweizerbart.de/journals/palb), the Geological Survey of Austria, and Walter de Gruyter GmbH.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Julia Gravendyck

JULIA GRAVENDYCK is a palynologist and botanist at the Freie Universität Berlin, Germany. She gained her MSc in 2016 at the Freie Universität Berlin in biology, specialising in biodiversity, ecology and evolution working on the palynology of the Carnian Stage for a pilot project on carbon capture and storage. Julia is currently working mainly on terrestrial Mesozoic palynology, integrating her botanical and biological perspective with palaeontology. She is involved in projects on palaeoenvironmental reconstruction, vegetation dynamics, teratology, stratigraphy and taxonomy in the Triassic of Germany and Early Cretaceous of Portugal. Julia is a past Student Director-at-Large of AASP – The Palynological Society, and currently serves on the Board of CPS - Collegium Palynologicum Scandinavicum.

Robert A. Fensome

ROBERT A. FENSOME is a research scientist with the Geological Survey of Canada (GSC), part of the federal department of Natural Resources Canada, in their Atlantic Division at the Bedford Institute of Oceanography, Dartmouth, Nova Scotia. During his 36-year tenure at the GSC, Rob has focussed mainly on Mesozoic and Cenozoic dinoflagellate cysts from offshore eastern Canada, but is now venturing into projects involving assemblages from north-western and Arctic Canada. While his mandate has involved primarily biostratigraphical and palaeoenvironmental studies, he also has a strong interest in dinoflagellate taxonomy and evolution, miospore taxonomy and geological outreach, co-authoring and co-editing two books for a general audience, one on the geology of Canada and one on the geology of Canada’s Maritime Provinces.

Martin J. Head

MARTIN J. HEAD is a palynologist, stratigrapher and a professor of Earth Sciences at Brock University, Canada. Previously at the University of Toronto and then the University of Cambridge, he maintains affiliations with these two institutions. Martin‘s research interests include the late Cenozoic record of dinoflagellate cysts and acritarchs, and the formal subdivision of the Quaternary System. He is Chair of the IAPT Nomenclature Committee for Fossils, Vice-Chair (and former Chair) of the International Subcommission on Quaternary Stratigraphy, and a former president of AASP – The Palynological Society and of the Canadian Association of Palynologists. Martin received a BSc from Aston University where he was introduced to palynology by Mavis Butterworth. His PhD was gained at the University of Aberdeen under the supervision of David Batten.

Patrick S. Herendeen

PATRICK S. HERENDEEN is a palaeobotanist and plant systematist at the Chicago Botanic Garden. He completed his PhD at Indiana University in 1990. He is currently working on Early Cretaceous and Late Jurassic fossil plants from Mongolia and Inner Mongolia, China. He also works on living and fossil members of the legume family. He currently serves as Secretary of the Nomenclature Committee for Fossils, as President of the International Association for Plant Taxonomy, and Chair of the International Association of Botanical and Mycological Societies.

James B. Riding

JAMES B. RIDING is a palynologist at the British Geological Survey in Nottingham, UK. He undertook the MSc in palynology at the University of Sheffield and, several years later, was awarded a PhD by the same institution. During 2004, he gained a DSc from the University of Leicester, where he did his Bachelor’s degree in geology. Jim’s interests include the Mesozoic and Cenozoic palynology of the world, palaeoenvironmental palynology, palynomorph floral provinces, forensic palynology, palynomorph preparation techniques, the history of palynology, the biostratigraphy, morphology, systematics and taxonomy of dinoflagellate cysts, and the geology of the Peak District, UK. Jim is a past Director-at-Large and President of AASP –The Palynological Society, and became Managing Editor in 2004. He was awarded the John Phillips Medal by the Yorkshire Geological Society in 2019 and is currently President-Elect of the International Federation of Palynological Societies.

Julien B. Bachelier

JULIEN B. BACHELIER is a professor of Botany and group leader at the Freie Universität Berlin, Germany. His curiosity for taxonomy started during his education at the National Museum of Natural History in Paris, when he thought he could revise the genus Cupressus during his Diploma. Quickly realizing this would never happen, the interest survived even after he moved into comparative structural studies. Under the supervision of Peter Endress and William (Ned) Friedman, he specialized in flower structure and development and in embryology, and their implications for the systematics and evolution of flowering plants. Dedicated to communicating his passion to his students, he has been associate editor for the journals of the Botanical Journal of the Linnean Society and Botany since 2016.

Nicholas J. Turland

NICHOLAS J. TURLAND is a botanist at the Botanischer Garten und Botanisches Museum Berlin, where he has worked since 2013 as head of publishing and editor of that institution’s journals Willdenowia and Englera. He is also deeply involved in the International Code of Nomenclature for algae, fungi, and plants, serving as Rapporteur-général for the Nomenclature Section of the International Botanical Congress (Shenzhen, 2017 and Madrid, 2024). He previously worked for 16 years at the Missouri Botanical Garden (St. Louis, USA) on the Flora of China project and before that for three years at the Natural History Museum (London, UK) on the Linnaean Plant Name Typification Project. Photo credit: Bernd Wannenmacher, Freie Universität Berlin.