Autapomorphies of Brycon orbignyanus:

1. Rhinosphenoid (47): (1> 0) absent. Reversal of synapomorphy 2 of the Characidae . Paralleled in nodes 207, 260, 280, and 298 and in Aphyocharax nattereri, Attonitus ephimeros, Bryconamericus scleroparius, Hollandichthys multifasciatus, Pseudocorynopoma doriae, and Salminus brasiliensis .

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

3. Number of teeth in inner premaxillary row (130): (0> 1) eight or more. Paralleled in the Aphyoditeinae, in node 170, and in Grundulus cochae, Phenacogaster tegatus, Prionobrama paraguayensis, and Salminus brasiliensis .

4. Number of cusps of anterior maxillary teeth (139): (0> 1) five or more cusps. Paralleled in the Rhoadsiinae, in nodes 273, 283, and 294, and in Bramocharax bransfordii, Gymnocharacinus bergii, Hemibrycon dariensis, Hyphessobrycon pulchripinnis, and Odontostoechus lethostigmus . Some trees: Paralleled in node 246.

5. Ventral margin of anterior ceratohyal (179): (0> 1) with notches for articulation of branchiostegal rays. Paralleled in nodes 167 and 189 and in Micralestes stormsi and Salminus brasiliensis .

6. Rows of gill rakers on first ceratobranchial (192): (0> 1) two. Reversal of synapomorphy 3 of node 179. Paralleled in the Iguanodectinae, in node 280, and in Bryconaethiops macrops, Carlana eigenmanni, Cheirodon interruptus, Hoplocharax goethei, Hyphessobrycon elachys, Odontostilbe microcephala, Parecbasis cyclolepis, Prodontocharax melanotus, and Rhaphiodon vulpinus . Some trees: Paralleled in node 249 and in Attonitus ephimeros .

7. Rows of gill rakers on second ceratobranchial (193): (0> 1) two. Paralleled in nodes 210, 225, 276, and 297 and in Hoplocharax goethei, Hyphessobrycon elachys, and Rhaphiodon vulpinus .

8. Humeral spot (341): (0> 1) horizontally-ovate. Paralleled in node 259 and in Acestrorhynchus pantaneiro, Jupiaba mucronata, and Roeboides microlepis .

Some trees:

9. Length of supraoccipital spine (53): (1> 0) extends posteriorly to, at least, middle length of neural complex of Weberian apparatus. (k11-14). Paralleled in the Serrasalmidae, in nodes 182 and 205, and in Piabucus melanostomus and Prochilodus lineatus . Some trees: Paralleled in Brycon meeki .

10. Coracoid foramen (243): (1> 0) absent or reduced to small pore. (k11-14).Reversalofsynapomorphy4ofnode179.Paralleledinnode 205 and in Salminus brasiliensis . Some trees: Paralleled in node302.

11. Dorsal-fin rays articulating with first dorsal pterygiophore (266): (0> 1) three or four. (k9-10). Paralleled in nodes 203 and 276 and in Metynnis maculatus and Salminus brasiliensis .

12. Anterior extension of adductor arcus palatini (336): (1> 0) covering most of dorsal surface of mesopterygoid. (k9-10). Paralleled in node 166 and in Creagrutus anary, Markiana nigripinnis, and Salminus brasiliensis .