Sprecher
Beschreibung
Direct evidence of animal–flower interactions in the fossil record is rare, but pollen preserved on or inside fossil animals provides unique insight into the evolution of pollination systems through time. In recent years, there has been accumulating evidence of flower visitation from the Cenozoic fossil record, and fossil flies, beetles, bees, birds, and bats bearing pollen have been discovered. Using fluorescence stereomicroscopy, micro-invasive sampling, and combined light, scanning electron, and transmission electron microscopy, fossil pollen extracted from animals and flowers has been identified with high taxonomic precision, allowing detailed reconstruction of Cenozoic pollination networks. The fossil record of direct bee-mediated pollination now extends back to the Paleocene (Selandian–Thanetian, 61.6–56 Ma) of Menat, France, representing the oldest known evidence of pollen transport by bees. Bee taxa including Probombus, Tithonanthidium, and Megachilinae carried pollen from Fabaceae, Fagaceae, Euphorbiaceae, Rutaceae, Cornaceae, Saururaceae, Nyssaceae, and Sapotaceae, indicating broad floral exploitation already during the Paleocene. The presence of Fabaceae pollen on multiple bee taxa suggests that legumes represented an important early floral resource. The Menat assemblage differs markedly from younger Eocene to Miocene biotas of Europe in both bee diversity and pollen composition. Middle Eocene assemblages from Messel and Eckfeld, Germany, preserve diverse bee–plant associations involving Araliaceae, Tilioideae, Euphorbiaceae, Nyssaceae, Elaeocarpaceae, Iridaceae, Olacaceae, Juglandaceae, and Sapotaceae. Recurrent associations, such as Araliaceae and Tilioideae pollen on several bee taxa (Electrapis, Protobombus), imply long-term continuity or widespread abundance of particular floral resources, whereas unique pollen occurrences may indicate more specialized interactions.