After Parker, 1981 and Martin & Davis, 2001

<==o Cirripedia Burmeister, 1834
   |--o Acrothoracica Gruvel, 1905
   |  |-- Trypetesidae Stebbing, 1910 [Apygophora Berndt, 1907]
   |  `--o Pygophora Berndt, 1907
   |     |-- Cryptophyalidae Gerstaecker, 1866
   |     `-- Lithoglyptidae Aurivillius, 1892
   |--o Rhizocephala Müller, 1862 (juuripäiset)
   |  |--o Kentrogonida Delage, 1884
   |  |  |-- Peltogastridae Lilljeborg, 1860 non Boschma
   |  |  |-- Sacculinidae Lilljeborg, 1860 non Boschma (pussiäyriäiset)
   |  |  `-- Lernaeodiscidae Boschma, 1928
   |  `--o Akentrogonida Häfele, 1911
   |     |?- Akentrogonidae Häfele, 1911 [not recognized by Martin &  Davis, 2001]
   |     |-- Chthamalophilidae Bocquet-Védrine, 1961
   |     |-- Clistosaccidae Boschma, 1928 [incl. Sylonidae]
   |     |-- Duplorbidae Høeg & Rybakov, 1992
   |     |-- Mycetomorphidae Høeg & Rybakov, 1992
   |     |-- Polysaccidae Lützen & Takahashi, 1996
   |     `-- Thompsoniidae Høeg & Rybakov, 1992
   `--o Thoracida Darwin, 1854 (varsinaiset siimajalkaiset)
      |--o Pedunculata Lamarck, 1818 (hanhenkaulamaiset siimajalkaiset)
      |  |--o Heteralepadomorpha Newman, 1987
      |  |  |-- Anelasmatidae Gruvel, 1905
      |  |  |-- Heteralepadidae Nilsson-Cantell, 1921
      |  |  |-- Koleolepadidae Hiro, 1933
      |  |  |-- Malacolepadidae Hiro, 1937
      |  |  |-- Microlepadidae Zevina, 1980
      |  |  `-- Rhizolepatidae Zevina, 1980
      |  |--o Iblomorpha Newman, 1987
      |  |  `-- Iblidae Leach, 1825
      |  |--o Lepadomorpha Pilsbry, 1916
      |  |  |-- Lepadidae Darwin, 1852 (hanhenkaulat)
      |  |  |-- Oxynaspididae Gruvel, 1905
      |  |  `-- Poecilasmatidae Annandale, 1909
      |  `--o Scalpellomorpha Newman, 1987
      |     |-- Calanticidae Zevina, 1978
      |     |-- Lithotryidae Gruvel, 1905
      |     |-- Pollicipedidae Leach, 1817
      |     `-- Scalpellidae Pilsbry, 1907
      `--o Sessilia Lamarck, 1818
         |--o Brachylepadomorpha Withers, 1923
         |  `-- Neobrachylepadidae Newman & Yamaguchi, 1995
         |--o Verrucomorpha Pilsbry, 1916
         |  |-- Neoverrucidae Newman, 1989
         |  `-- Verrucidae Darwin, 1854
         `--o Balanomorpha Pilsbry, 1916 (merirokkomaiset siimajalkaiset)
            |--o Chionelasmatoidae Buckeridge, 1983
            |  `-- Chionelasmatidae Buckeridge, 1983
            |--o Pachylasmatoidea Utinomi, 1968
            |  `-- Pachylasmatidae Utinomi, 1968
            |--o Chthamaloidea Darwin, 1854
            |  |-- Catophragmidae Utinomi, 1968
            |  `-- Chthamalidae Darwin, 1854
            |--o Coronuloidea Leach, 1817
            |  |-- Chelonibiidae Pilsbry, 1916
            |  |-- Coronulidae Leach, 1817
            |  `-- Platylepadidae Newman & Ross, 1976
            |--o Tetraclitoidea Gruvel, 1903
            |  |-- Bathylasmatidae Newman & Ross, 1976
            |  `-- Tetraclitidae Gruvel, 1903
            `--o Balanoidea Leach, 1817 (merirokonsukuiset siimajalkaiset)
               |-- Archaeobalanidae Newman & Ross, 1976
               |-- Balanidae Leach, 1817 (merirokot)
               `-- Pyrgomatidae Gray, 1825

Reference(s):