Can in-situ pollen link fossil plants to floral visitors?

Flowering plants and insects are the most diversified and widespread groups of plants and animals on earth. The parallel diversification of flowering plants and various flower visiting/feeding insect lineages, including beetles, bees, butterflies, moths, and flies, suggests a mutualistic interaction between flowering plants and their major pollinators. Flowering plant interaction with pollinators seems also to be the driver behind specialization and subsequent diversification in both plants and insects. To test hypotheses regarding evolutionary dynamics of flowers and their insect visitors, the examination of the fossil record of flower-insect interactions is essential. To investigate the Paleogene co-evolution between insects and flowering plants in- situ pollen from the anthers of fossil flowers and from the exterior or internal organs of fossil insects will be studied. This project will be the first test whether in-situ fossil pollen can link insects and flowers from the same fossil assemblage. It will be the first study to include a large number of different insects and flowers from the same fossil assemblage, and from different periods of the Paleogene. In addition, it will provide large-scale direct evidence for flower-insect interaction during the time of major radiations of both insect pollinators and flowering plants, adding crucial information to the evolutionary history of interactions between flowers and their insect visitors. Finally, fossil pollen from three sources of the same assemblages will be investigated; i.e. dispersed pollen from sedimentary rock samples, in-situ pollen from fossil flowers, and pollen from the exterior or internal organs of fossil insects. This will for the first time show how representative dispersed palynofloras are of the "actual" paleovegetation.