Coleoptera represent one of evolution's greatest success stories, and many have attempted to explain its diversification through phylogenetic comparative analyses. Yet the relationships among the major branches of the Coleoptera tree remain obscure. Recent morphological work has suggested a close relationship between the huge series Staphyliniformia and Scarabaeiformia, reviving a long discredited lineage, 'Haplogastra'. We analyzed 18S rDNA sequences, alone and in combination with morphological data, for 110 coleopteran taxa, including representatives of all other major beetle lineages. A monophyletic Haplogastra is generally supported, though monophyly of neither series within it is. Topological resolution among subordinate families varies substantially among analyses, though several groupings of subfamilies and families are consistent and well supported.