Autapomorphies of Exodon paradoxus:

1. Contact between frontals anteriorly to frontal fontanel (21): (0> 1) present. Reversal of synapomorphy 4 of node 206. Paralleled in Bario steindachneri, Galeocharax humeralis, Hyphessobrycon pulchripinnis, and Odontostoechus lethostigmus . Some trees: Paralleled in Knodus breviceps .

2. Morphology of premaxillary, maxillary, and dentary teeth (118): (1> 0) all teeth conical, caniniform or mamilliform. Paralleled in the Heterocharacinae, in nodes 174, 181, and 211, and in Axelrodia lindeae and Grundulus cochae .

3. Form of quadrate (150): (0> 1) with anterodorsal portion equal or longer than ventral region. Paralleled in the Pseudochalceus clade, in nodes 170, 176, 211, and 299, and in Hoplias cf. malabaricus .

4. Position of longitudinal cartilage dorsal to ectopterygoid (161): (0> 1) displaced laterally and separated from medial margin of mesopterygoid. Paralleled in nodes 211 and 300.

5. Relative position of dorsal-fin anterior insertion (265): (1> 0) anterior to or at vertical through pelvic-fin origin. Paralleled in node 282 and in Creagrutus anary, Moenkhausia xinguensis, and Parecbasis cyclolepis .

6. Bony hooks on fin rays (307): (1> 0) absent. Paralleled in the Gymnocharacinae, in nodes 207, 283, 297, and 301, and in Astyanax paris, Bryconamericus mennii, Inpaichthys kerri, Pseudochalceus kyburzi, and Rhoadsia altipinna . Some trees: Paralleled in Hasemania nana and Hyphessobrycon elachys .

7. Circulii on posterior field of scales (319): (1> 0) present. Reversal of synapomorphy 3 of node 206. Paralleled in node 261 and in Phenagoniates macrolepis and Roeboides microlepis .