A new species of Ptychochromis from northeastern Madagascar (Teleostei: Cichlidae), with an updated phylogeny and revised diagnosis for the genus Author Sparks, John S. Author Stiassny, Melanie L. J. text Zootaxa 2010 2341 33 51 journal article 10.5281/zenodo.193312 becbe9e7-b072-464c-a565-fb0915d012f4 1175-5326 193312 Ptychochromis Steindachner, 1880 Type species: Ptychochromis oligacanthus ( Bleeker, 1868 ) Generic diagnosis. A ptychochromin genus diagnosed by the presence of a free second epibranchial toothplate ( Stiassny & Sparks, 2006: Fig. 7 A ), exclusion of the second infraorbital bone (IO2) from the orbit by IO3 ( Stiassny & Sparks, 2006: Fig. 8 F ), a prominent palatine groove ( Stiassny & Sparks, 2006: Fig. 6 F– G ), ventrally displaced insertion of the palatine-palatine ligament compared to other ptychochromin genera (Stiassny & Sparks: Fig. 6 F–G), a horizontally oriented palatine bone with an elongate palatine prong and weakly elevated lateral ethmoid process ( Fig. 2 ; Stiassny & Sparks, 2006 : Fig. 6 G; modified in members of the “western clade”), and anterior displacement of the supraneural bones such that the anterior element comes to overlie the dorsoposterior margin of the supraoccipital crest ( Fig. 3 A–C; lacking in members of the “western clade”). Note that due to a typographic error in our prior diagnosis for Ptychochromis ( Stiassny & Sparks, 2006: 14 ) we erroneously state that IO3 is excluded from the orbital margin by IO2, however, this feature is correctly described above (i.e., IO2 excluded from orbital margin by IO3). The remainder of the text, character description, cladogram, figures, and dataset are correct with respect to the configuration, coding, and interpretation of this feature ( Stiassny & Sparks, 2006: character 11 ).