The middle Eocene bee faunas of Eckfeld and Messel, Germany (Hymenoptera, Apoidea)

The Middle Eocene (Lutetian) bee faunas of Eckfeld and Messel, Germany are revised. In addition to the previously known Electrapis electrapoides (Lutz), five additional species are recognized. Four new species of the Electrapini (Apidae: Apinae) are described: Electrapis micheneri Wappler and Engel, E. prolata Engel and Wappler, Protobombus pristinus Wappler and Engel, and P. messelensis Engel and Wappler. In addition, the new genus Pygomelissa Engel and Wappler is proposed for Pygomelissa lutetia Engel and Wappler new species, which cannot presently be classified into any tribe of the Apidae. The tribe Megachilini (Megachilidae: Megachilinae) is also recorded from Eckfeld but in the absence of any body fossil. Megachilines include the leaf-cutter bees (Megachile) and from the occurrence of the distinctive semicircular damage they produce in leaves, we conclude that such bees were also present in the fauna. The bee fauna is compared with that of the contemporaneous Baltic amber. As with Baltic amber, the majority of bee specimens are from the advanced eusocial lineages of the corbiculate Apinae. Lastly, comments are made on the phylogenetic and paleobiological significance of the faunas.