After Systema Naturae 2000 and Skovsted, Peel & Atkins, 2004

<==o †Hyolitha
   |?- †Haplophrentis carinatus
   |?-o †Triplicatella Conway Morris, in Bengtson et al., 1990
   |  |-- †T. disdoma Conway Morris, in Bengtson et al., 1990
   |  |-- T. sinuosa Skovsted, Peel & Atkins, 2004
   |  `-- T. peltata Skovsted, Peel & Atkins, 2004
   |--o †Hyolithida Syssoiev, 1957
   |  |-- †Dilytes
   |  |-- †Elegantilites
   |  |-- †Eumorpholites
   |  |-- †Gompholites
   |  |-- †Hyolithes
   |  |-- †Joachimilites
   |  |-- †Maxilites
   |  `-- †Nevadalites
   `--o †Orthothecida Marek, 1966
      |-- †Bactrotheca
      |-- †Nephrotheca
      |-- †Orthotheca
      |-- †Quadrotheca
      `-- †Tcharatheca

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