The present paper provides a revision of the pycnodontiform fish genera that are based on articulated material. The results of the first cladistic analysis on the interrelationships of the order Pycnodontiformes Berg, 1937 are also presented: it is based on 105 characters for 33 taxa. The monophyly of the order, of the suborder Pycnodontoidei Nursall, 1996, and of the family Pycnodontidae Agassiz, 1833 sensu Nursall 1996b (in large sense) are confirmed; the "suborder Gyrodontoidei" appears, in contrast, as a paraphyletic group. The revision of the historic nomenclatural problems and the hypothesis of phylogenetic relationships show that the genera Eomesodon Woodward, 1918, CoelodusPalaeobalistum Blainville, 1818, as previously recognized, were not natural assemblages. The new genera Apomesodon n. gen., Ocloedus n. gen., Oropycnodus n. gen., and Abdobalistum n. gen., together with two new species (Apomesodon surgens n. gen., n. sp. and Abdobalistum thyrsus n. gen., n. sp.), are erected to locate former species of those non-monophyletic genera. The subfamilies Proscinetinae n. rank, Pycnodontinae n. rank, and Nursalliinae n. rank, are also proposed, together with the superfamily Pycnodontoidea n. rank, which gathers the sister-groups Coccodontidae and Pycnodontidae. A completely revised systematic palaeontology of the Pycnodontiformes is provided.
Actinopterygii, Pycnodontiformes, revision, cladistics, phylogeny, new genera, new species