Figure 4

A remarkable example of morphological convergence. The genus Hexanematichthys sensu Kailola [15] includes two species ('Sciades' sagor and S. mastersi) and is defined by the presence of a broad and depressed head, a short and broad supraoccipital process (SP) and a large butterfly-shaped nuchal plate (NP), among other features. While the neurocrania of S. sagor and S. mastersi are most similar in this sample, the molecular evidence suggests that they are more closely related to Arius nenga (India-SE Asia clade) and Cochlefelis dioctes (Australia-New Guinea clade), respectively (see Figure 3). Also, Templeton and SH tests reject monophyly of Hexanematichthys (see Table 2). (A), AUM 46280, 87 mm cranial length (CL); (B), AUM 50242, 131 mm CL; (C), AUM 47562, 117 mm CL; (D), AUM 47507, 170 mm CL.