Autapomorphies of Bryconops melanurus:

1. Articulation between second and third infraorbitals (62): (0> 2) posteroventrally angled. Paralleled in the Characinae, in nodes 176 and 300, and in Hollandichthys multifasciatus .

2. Cusps of teeth on outer premaxillary row (125): (0> 1) five or more cusps. Paralleled in nodes 265 and 294 and in Brycon orbignyanus, Gymnocharacinus bergii, Micralestes stormsi, and Nematocharax venustus . Some trees: Paralleled in Bryconamericus agna .

3. Number of gill rakers on first hypobranchial and ceratobranchial (196): (0> 1) ten or fewer. Paralleled in the Characinae and in Hyphessobrycon pulchripinnis, Iguanodectes geisleri, and Moenkhausia sanctaefilomenae . Some trees: Paralleled in node 196 and in Hemigrammus erythrozonus and Hyphessobrycon herbertaxelrodi .