Autapomorphy of Astyanax mexicanus:

1. Posterior extent of ventral process of quadrate (151): (0> 1) falling short of posterior margin of symplectic. Paralleled in the Hyphessobrycon luetkenii clade and Iguanodectinae, in nodes 284, 289, and 298, and in Astyanax cf. rutilus, Aulixidens eugeniae, Cyphocharax spilotus, Diapoma speculiferum, Hemiodus cf. thayeria, Metynnis maculatus, Micralestes stormsi, Moenkhausia sanctaefilomenae, Nematocharax venustus, Probolodus heterostomus, Psellogrammus kennedyi, and Pseudocorynopoma doriae . Some trees: Paralleled in node 302.