After Bulman, 1955, Parker, 1982, and Cameron, 2000-2004

<==o Enteropneusta Gegenbaur, 1870 [Enteropneusti Gegenbaur, 1870] (acorn worms; terhomadot)
   |?- Tornaria setoensis Miyashita, 1925 [larva]
   |?- Tornaria delsmanii Stiasny-Wijnhoff & Stiasny, 1927 [larva]
   |?- Tornaria ijimai Stiasny, 1928 [larva]
   |?- Tornaria yongei Trewavas, 1931 [larva]
   |?- Tornaria cairnsiensis Trewavas, 1931 [larva]
   |?- Tornaria colmani Trewavas, 1931 [larva]
   |?- Tornaria russelli Trewavas, 1931 [larva]
   |-- Torquarator bullocki Holland, Clague, Gordon, Gebruk, Pawson & Vecchione, 2005 [Torquaratoridae Holland, Clague, Gordon, Gebruk, Pawson & Vecchione, 2005]
   |--+-- †Spartobranchus tenius Caron, Conway Morris & Cameron, 2013; M.Camb. WNAm.
   |  `-- Harrimanidae [incl. Protoglossidae]
   |-- Saxipedium coronatum Woodwick & Sensenbaugh, 1985 [Saxipendiidae]
   |-- Ptychoderidae
   `--o Spengalidae
      |--o Spengelia
      |  |-- S. alba Willey, 1899
      |  |-- S. amboinensis Spengel, 1907
      |  |-- S. discors Spengel, 1907
      |  |-- S. maldivensis Punnett, 1903
      |  |-- S. porosa Willey, 1898
      |  `-- S. sibogae Spengel, 1907
      |--o Glandiceps Spengel, 1893
      |  |-- G. abyssicola Spengel, 1893
      |  |-- G. bengalensis Rao, 1955
      |  |-- G. coromandelicus Spengel, 1907
      |  |-- G. eximius Spengel, 1907
      |  |-- G. hacksi Marion, 1885
      |  |-- G. malayanus Spengel, 1907
      |  `-- G. talaboti Marion, 1876
      |--o Schizocardium
      |  |-- S. peruvianum Spengel, 1893
      |  `-- S. braziliense Spengel, 1893
      `-- Willeya bisulcata Punnett, 1906

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