Phylum Tardigrada Doyère, 1840 - tardigrades Order Heterotardigrada Marcus, 1927 see Class Heterotardigrada Marcus, 1927 Suborder Arthrotardigrada Marcus, 1927 see Order Arthrotardigrada Marcus, 1927 Family Halechiniscidae Thulin, 1928 Subfamily Styraconyxinae Kristensen & Renaud-Mornant, 1983