The earliest large carpenter bee (Xylocopa) and its adhering pollen (Araliaceae, Theaceae)

The association of pollinators with their host plants is a critical element of ecosystem functioning and one that is usually determined indirectly in the fossil record from specific morphological traits of flowers or putative pollinating animals. The exceptionally fine preservation at Messel, Germany, offers an excellent source of data on pollen from fossil flowers as well as preserved adhering to insects as direct evidence of their association with specific floral lineages. Here, we report on pollen recovered from the body and legs of a large carpenter bee (Apidae: Xylocopinae: Xylocopini) from the Eocene of Messel. The fossil is the earliest occurrence of the tribe Xylocopini and represents an extinct subgenus and species, described as Xylocopa (Apocolyx) primigenia subgen. et sp. nov. Two eudicot pollen types were recovered from the bee, one of the family Theaceae (Asterids: Ericales) and another of Araliaceae (Euasterids: Apiales). The pollen grains are compared with various extinct and extant pollen types, and data on floral visitors to modern theaceous and araliaceous flowers are explored in relation to understanding the association of the fossil carpenter with these floral types in the paratropical Eocene biota of Messel.