The phylogeny of the Histeroidea (Coleoptera: Staphyliniformia).

For its size (ca. 4000 species) the Histeridae is one of the most ecologically and morphologically diverse families of beetles. Its mostly predaceous members occupy a wide variety of habitats for which their morphologies may be highly modified. Previous attempts to resolve the phylogeny of the family based on morphological data have left many difficult issues unresolved. This study is the first to utilize either larval or molecular (18S rDNA) data in combination with adult morphology in an attempt to resolve these issues. We compare the performance of optimization alignment with a fixed positional homology approach, over a range of parameter space. Optimizing alignment parameters for combined analyses of 18S and morphology for both approaches resulted in very similar topologies. Contrary to previous hypotheses which held the cylindrical, subcortical forms of the family (e.g., Niponius, Trypanaeus, Trypeticus) to be the most primitive, our analyses find these to be highly specialized forms derived from within other more generalized taxa. Basal lineages within the family instead include Onthophilus, Anapleus, and Dendrophilus, all of which are ovoid, mainly generalist forms.