New specimens of the Eocene Messelirrisoridae (Aves:Bucerotes), with comments on the preservation of uropygial gland waxes in fossil birds from Messel and phylogenetic affinities of Bucerotes
G. Mayr, New specimens of the Eocene Messelirrisoridae (Aves:Bucerotes), with comments on the preservation of uropygial gland waxes in fossil birds from Messel and phylogenetic affinities of Bucerotes, Palaontologische Zeitschrift Palaontologische Zeitschrift (Print);Journal of Palaontologische Gesellschaft Scientific contributions to palaeontology, 80(4), 2006, pp. 390-405