Diplogasterida was an order of nematodes. It was sometimes placed in a monotypic subclass Diplogasteria, but molecular phylogenetic evidence has shown it to be embedded in the family Rhabditidae (formerly Rhabditina). The confusion of having a hierarchical nesting of groups that were formerly mutually exclusive has led to a profusion of names. Although completely revised taxonomy of nematodes that builds on recent classification systems[1][2] as well as recent phylogenetic evidence[3][4] is still necessary, most contemporary taxonomic studies now treat all groups listed under "Diplogasterina" below as a single family, Diplogastridae.