Phylum Tardigrada Doyère, 1840 - tardigrades
   Order Heterotardigrada Marcus, 1927 see Class Heterotardigrada Marcus, 1927
     Suborder Arthrotardigrada Marcus, 1927 see Order Arthrotardigrada Marcus, 1927
       1 Family Halechiniscidae Thulin, 1928
       2 Family Batillipedidae Ramazzotti, 1962
       3 Family Stygarctidae Schulz, 1951
       4 Family Renaudarctidae Kristensen & Higgins, 1984
       5 Family Coronarctidae Renaud-Mornant, 1974