Autapomorphies of Moenkhausia dichroura:

1. Alignment of cusps of medial teeth on inner premaxillary row (127):(1>0)forming anteriorly concave semicircle from ventral view. Paralleledinnodes 183 and 262.Sometrees:Paralleledinnode 302.

2. Number of gill rakers on first hypobranchial and ceratobranchial (195): (1> 0) 16 or more. Paralleled in nodes 177 and 183 and in Astyanax latens, A. cf. rutilus, A. pelegrini, Hoplias cf. malabaricus, Hyphessobrycon socolofi, Parecbasis cyclolepis, Piaractus mesopotamicus, and Stichonodon insignis .

3. Base of second pectoral ray (231): (1> 0) large and partially overlapping base of first pectoral ray from medial view. Paralleled in nodes 164 and 301 and in Prionobrama paraguayensis and Tetragonopterus argenteus .