Phylum Hemichordata Bateson 1885 (acorn worm)
Parent taxon: Ambulacraria according to C. Nielsen 2012
See also Edgecombe et al. 2011, Sepkoski 2002 and Zrzavy et al. 1998
Sister taxa: Cambroernids, Echinodermata, Vetulocystida, Yanjiahella
Subtaxa: Enteropneusta Pterobranchia