Order Arthrotardigrada Marcus, 1927 - arthrotardigrades Family Stygarctidae Schulz, 1951 Genus Megastygarctides McKirdy et al., 1976 1 Megastygarctides christinae H.J. Guldberg & R.M. Kristensen, 2006 2 Megastygarctides gerdae H.J. Guldberg & R.M. Kristensen, 2006 3 Megastygarctides isounguis Renaud-Mornant, 1981 4 Megastygarctides setoloso Morgan & O'Reilly, 1988