Worms that suck: Phylogenetic analysis of Hirudinea solidifies the position of Acanthobdellida and necessitates the dissolution of Rhynchobdellida

•Leeches, crayfish worms, and Acanthobdellida form a clade sister to Lumbriculidae.•Leeches and Acanthobdellida comprise the sister clade to crayfish worms.•These relationships shed light on the origin of bloodfeeding in annelids.•Three suborders are created to reflect relationships of major leech lineages.•Classic phylogenetic studies should be reassessed by adding, and screening, data.