Cyclorhagida

 ( Kinorhyncha ) 

Cyclorhagida is a class of Kinorhyncha, small marine Invertebrate that are widespread in mud or sand at all depths as part of the meiobenthos, commonly known as mud dragons.

• Order Echinorhagata Sørensen et al., 2015
• Echinoderidae Zelinka, 1894Zelinka, C. (1894). Über die Organisation von Echinoderes. Verhandlungen der Deutschen Zoologischen Gesellschaft, 4, 46–49.
• Order Kentrorhagata Sørensen et al., 2015
• Antygomonidae Adrianov & Malakhov, 1994Adrianov, A. V. & Malakhov, V. V. (1994). Kinorhyncha: structure, development, phylogeny and taxonomy. Moscow: Nauka.
• Cateriidae Gerlach, 1956Gerlach, S. (1956). Über einen aberranten Vertreter der Kinorhynchen aus dem Küstengrundwasser. Kieler Meeresforschungen, 12, 120–124.
• Centroderidae Zelinka, 1896
• Semnoderidae Remane, 1929Remane, A. (1929). In Grimpe, J. & Wagler, E. (Eds.), Die Tierwelt der Nord- und Ostee (pp. 1–156). Leipzig: Akademische Verlagsgesellschaft.
• Zelinkaderidae Higgins, 1990Higgins, R. P. (1990). Zelinkaderidae, a new family of cyclorhagid Kinorhyncha. Smithsonian Contributions to Zoology, 500, 1–26.
• Order Xenosomata Zelinka, 1907
• Campyloderidae Remane, 1929
• Family incertae sedis
• Tubulideres Sørensen, Heiner, Ziemer & Neuhaus, 2007Sørensen, M., Heiner, I., Ziemer, O. & Neuhaus, B. (2007). Tubulideres seminoli gen. et sp. nov. and Zelinkaderes brightae sp. nov. (Kinorhyncha, Cyclorhagida) from Florida. Helgoland Marine Research, 61(4), 247–265.
• Wollunquaderes Sørensen & Thormar, 2010Sørensen, M. & Thormar, J. (2010). Wollunquaderes majkenae gen. et sp. nov. – A new cyclorhagid kinorhynch genus and species from the Coral Sea, Australia. Marine Biodiversity, 40, 261–275.