Sprecher
Beschreibung
Biotic pollination represents a key mutualistic interaction in terrestrial ecosystems, strongly influencing the evolutionary history of plants and animals, yet its origins remain debated. Palynivory, the consumption of spores and/or pollen, has been proposed as a precursor to insect-mediated pollination. Here, we review the fossil record of invertebrate bromalites (coprolites and gut contains) containing spores and pollen from non-angiosperm plants across the Paleozoic and Mesozoic, synthesizing data accumulated since earlier studies. Our analysis reveals a stepwise evolutionary trajectory. Early records from the Silurian–Devonian are dominated by detritivorous consumption of a variety of spores, indicating opportunistic feeding. During the Carboniferous, increasing plant and insect diversification coincides with greater dietary specialization and the first evidence of pollen consumption. In the Permian, a shift from sporivory- to pollinivory-dominated systems occurs, likely linked to environmental changes and the rise of seed plants. In contrast, the Mesozoic record is sparse, limiting interpretation of later evolutionary trends. The fossil record of palynivory is strongly biased by preservation, methodological limitations, and uncertainties in the botanical affinity of the spores and pollen. Although often considered a precursor to biotic pollination, direct links between pollen consumption and gymnosperms pollination mutualisms remain difficult to establish. Among the different non-angiosperm plants supposed to be involved in pollination, only cheirolepidiacean pollen grains have been found in bromalites so far. This review highlights the need for standardized and targeted methodologies to better document palynivory and clarify its role in the evolution of plant–insect interactions.