After Carroll, 1988 and Nelson, 1994

<==o Gymnotiformes (veitsikalat)
   |--o Sternopygoidei
   |  |-- Sternopygidae (“lasiveitsikalat”)
   |  |-- Rhamphichthyidae (kärsäveitsikalat)
   |  |-- Hypopomidae
   |  `-- Apteronotidae (pyrstöveitsikalat)
   `--o Gymnotoidei
      |-- Electrophoridae (sähköankerias)
      `-- Gymnotidae (varsinaiset veitsikalat)

Reference(s):