The Sulae were traditionally included in the Pelecaniformes in its obsolete paraphyletic circumscription, but pelicans, the namesake family of the Pelecaniformes, are actually more closely related to herons, ibises and spoonbills, the hamerkop, and the shoebill than to the sulids and allies. In recognition of this, the Sulae have been proposed for separation in a new order Phalacrocoraciformes, which also includes the frigatebirds (Fregatidae), as well as one or more prehistoric lineages that are entirely extinct today. The IOC World Bird List uses Suliformes as the proposed order name.