After Carroll, 1988, Long 1990, with fossil species from Williams, 1999-2000

<==o †Petalodontidae Newberry & Worthen, 1866
   |-- †Ageleodus pectinatus (Agassiz, 1838), Dev. Miss. Aust. Eu. NA.
   |--o †Antliodus [Chomatodus] Miss. NA. Eu. As.
   |  |-- †A. mucronatus Newberry & Worthen, 1866
   |  |-- †A. sp.
   |  `-- †A. wisei (Woodward, 1919)
   |--o †Chomatodus [Chromatodus, Palaeobatis, Petalodus, Psammodus] Miss. Eu. Carb. NA.
   |  |-- †C. linearis Agassiz, 1838
   |  |-- †C. multiplicatus
   |  `-- †C. sp.
   |--o †Ctenoptychius [Petalodus, Calloptistalus] Penn. Eu. 
   |  |-- †C. apicalis Agassiz, 1838 [Petalodus]
   |  |-- †C. pectinatus [Calloptistalus]
   |  `-- †C. sp.
   |-- Glyphanodus tenuis (Davis, 1883a) [Glyphanodon] Miss. Eu.
   |--o †Harpacodus [Ctenopetalus, Ctenoptychius, Petalodus) Miss. Eu. 
   |  |-- †H. dentatus (Owen, 1845b) [Petalodus]
   |  `-- †H. serratus [Ctenopetalus]
   |--o †Lisogodus Miss. NA. 
   |  |-- †L. curtus St. John & Worthen, 1875a
   |  `-- †L. sp.
   |-- †Neopetalodus japonicus - M. Perm. EAs.
   |-- †Paracymatodus plicatulus (Trautschold, 1879b) [Cymatodus Cimatodus] Miss. EEu.
   |--o †Petalodus Owen, 1840 [Ctenopetalus, Getalodus, Sicarius] Miss. Eu. U. Dev. or L. Carb. EAs. 
   |  |-- †P. acuminatus (Agassiz, 1838)
   |  |-- †P. allegheniensis
   |  |-- †P. laevissimus
   |  |-- †P. ohioensis Safford, 1853
   |  `-- †P. sp.
   |--o †Polyrhizodus [Ctenoptychius, Dacatylodus, Petalodus, Rhomboderma) Miss. Eu. EEu. Carb. NA. 
   |  |-- †P. magnus McCoy, 1848a
   |  |-- †P. digitatus
   |  `-- †P. sp. [Petalodus grandis]
   |--o †Serratodus Miss. L. Perm. Eu. 
   |  |-- †S. elegans (de Koninck, 1878a)
   |  `-- †S. sp.
   `--o †Tanaodus [Chomatodus, Tonaodus) Miss. NA. Eu. 
      |-- †T. bellicinctus St. John & Worthen, 1875a
      |-- †T. polymorphus
      `-- †T. sp.

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