[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Phylum Annelida Lamarck, 1809 - segmented worms
     Class Polychaeta Grube, 1850 - polychaetes
       01 Family Acoetidae Kinberg, 1856
       02 Family Acrocirridae K. Banse, 1969
       03 Family Aeolosomatidae Beddard, 1895
       04 Family Alciopidae Ehlers, 1864
       05 Family Ampharetidae Malmgren, 1865
       06 Family Amphinomidae Savigny, 1818
       07 Family Antonbruuniidae K. Fauchald, 1977
       08 Family Aphroditidae Malmgren, 1867
       09 Family Apistobranchidae Mesnil & Caullery, 1898
       10 Family Arabellidae Hartman, 1944 see Family Oenonidae Kinberg, 1865
       11 Family Arenicolidae Johnston, 1835
       12 Family Calamyzidae Hartmann-Schröder, 1971
       13 Family Capitellidae Grube, 1862
       14 Family Chaetopteridae Malmgren, 1867
       15 Family Chrysopetalidae E. Ehlers, 1864
       16 Family Cirratulidae Ryckholt, 1851
       17 Family Cossuridae Day, 1963
       18 Family Ctenodrilidae Kennel, 1882
       19 Family Diurodrilidae Kristensen & Niilonen, 1982
       20 Family Dorvilleidae Chamberlin, 1919
       21 Family Eulepethidae Chamberlin, 1919
       22 Family Eunicidae Savigny, 1818
       23 Family Euniphysidae Shen & Wu, 1991 see Family Eunicidae Savigny, 1818
       24 Family Euphrosinidae Williams, 1851
       25 Family Fauveliopsidae Hartman, 1971
       26 Family Flabelligeridae de Saint-Joseph, 1894
       27 Family Glyceridae Grube, 1850
       28 Family Goniadidae Kinberg, 1866
       29 Family Hesionidae Grube, 1850
       30 Family Histriobdellidae Vaillant, 1890
       31 Family Ichthyotomidae Eisig, 1906
       32 Family Iopsilidae see Family Iospilidae Bergström, 1914
       33 Family Lacydoniidae Bergström, 1914
       34 Family Longosomatidae Hartman, 1944
       35 Family Lopadorrhynchidae Claparède, 1868
       36 Family Lumbrineridae Schmarda, 1865
       37 Family Magelonidae Cunningham & Ramage, 1888
       38 Family Maldanidae Malmgren, 1867 - bamboo worms
       39 Family Myzostomidae
       40 Family Nephtyidae Grube, 1850
       41 Family Nereididae Johnston, 1865
       42 Family Nerillidae Levinsen, 1883
       43 Family Oenonidae Kinberg, 1865
       44 Family Onuphidae Kinberg, 1865
       45 Family Opheliidae Malmgren, 1867
       46 Family Orbiniidae Hartman, 1942
       47 Family Oweniidae Rioja, 1917
       48 Family Paralacydoniidae Pettibone, 1963
       49 Family Paraonidae Cerruti, 1909
       50 Family Parergodrilidae Reisinger, 1960
       51 Family Pectinariidae de Quatrefages, 1865
       52 Family Pholoidae Kinberg, 1858
       53 Family Phyllodocidae Ørsted, 1843
       54 Family Pilargidae de Saint-Joseph, 1895
       55 Family Pisionidae Ehlers, 1901
       56 Family Poecilochaetidae Hannerz, 1956
       57 Family Polygordiidae Czerniavsky, 1881
       58 Family Polynoidae Kinberg, 1856
       59 Family Pomatodrilidae see Family Potamodrilidae
       60 Family Pontodoridae Bergström, 1914
       61 Family Protodrilidae Czerniavsky, 1881
       62 Family Psammodrilidae Swedmark, 1953
       63 Family Questidae O. Hartman, 1966
       64 Family Sabellariidae Savigny, 1818
       65 Family Sabellidae Malmgren, 1867
       66 Family Saccocirridae Czerniavsky, 1881
       67 Family Scalibregmatidae Malmgren, 1867
       68 Family Serpulidae Savigny, 1818
       69 Family Sigalionidae Kinberg, 1856
       70 Family Sphaerodoridae Malmgren, 1867
       71 Family Spintheridae Augener, 1913
       72 Family Spionidae Grube, 1850
       73 Family Spirorbidae (Chamberlin, 1919) Pillai, 1970
       74 Family Sternaspidae Carus, 1863
       75 Family Syllidae Grube, 1850
       76 Family Terebellidae Grube, 1850
       77 Family Tomopteridae Johnston, 1865
       78 Family Trichobranchidae Malmgren, 1865 see Family Terebellidae Grube, 1850
       79 Family Trochochaetidae Pettibone, 1963
       80 Family Typhloscolecidae Uljanin, 1878