They are tiny and yet a veritable source of geological history: pollen is usually just 20 micrometres, or 0.02 millimetres, in size. Using these tiny particles, a research team from the Leibniz Universität Hannover (LUH) and the Rheinische Friedrich-Wilhelms-Universität Bonn has now succeeded in pinpointing the earliest appearance of flowering plants, known as angiosperms. While it was previously assumed that dicotyledonous flowering plants, the eudicotyledols, first appeared around 121 million years ago, the scientists in the project ‘Palynological investigations into the earliest phase of angiosperm evolution’, funded by the German Research Foundation, were able to prove by means of new findings that flowering plants existed at least two million years earlier. The project ran from October 2020 up to March 2025 and was funded with 255,000 euros.
According to current research, the first land plants ever existed in the Ordovician period, around 485 to 444 million years ago. First there were mosses, later came ferns, ginkgos and conifers. Flowering plants – today the most diverse genus of land plants – only appeared more than 300 million years later. Researchers have now been able to identify the oldest pollen produced by dicotyledonous flowering plants in rock sequences from Portugal. Prof Dr Ulrich Heimhofer, Institute of Earth System Sciences at LUH, and Dr Julia Gravendyck, Institute of Organismic Biology, University of Bonn, and their team identified fossil angiosperm pollen from coastal marine deposits from the Lusitanian Basin in Portugal; they have dated these to around 123 million years ago.
How and from which plants the flowering plants developed is still unclear. However, it is a fact that angiosperms had a lasting influence on the development of life on our planet. They enriched the diversity of species on Earth immensely. ‘Biological diversity was significantly changed by the appearance of flowering plants,’ says Professor Heimhofer. ‘But exactly when and where this development started has been one of the great mysteries of biology since Darwin's time,’ says Dr Gravendyck. It also remains unclear what influence plate tectonic processes and large-scale climate changes had as possible drivers for the development of angiosperms.
The results were published this week in the journal ‘Proceedings of the National Academy of Sciences of the United States of America (PNAS)’: Gravendyck et al. (2025): Barremian tricolpate pollen from Portugal - new evidence for the age of eudicot-related angiosperms. PNAS. DOI: 10.1073/pnas.2421470122.
