When is it justified to change the higher level classification of a well known taxon? The recent availability of large amounts of DNA sequence data from phylogenetic studies has raised the profile of this age-old problem, with the additional complication that DNA data may not be congruent with morphology data. We now have a substantial amount of DNA sequence available for reconstructing the phylogeny of swallowtail butterflies of the subfamily Parnassiinae, and this clearly supports the recognition of an additional tribe, the Luehdorfiini, in spite of the complete absence of support for this grouping from morphological characters. Nonetheless, morphology does not substantially conflict with this grouping, and therefore we believe that the Luehdorfiini should be formally recognized based on the DNA data alone.