CHARACIFORMES (Datovo & Castro, 2012)

Datovo, Aléssio & Vari, Richard P., 2014, The adductor mandibulae muscle complex in lower teleostean fishes (Osteichthyes: Actinopterygii): comparative anatomy, synonymy, and phylogenetic implications, Zoological Journal of the Linnean Society 171 (3), pp. 554-622 : 613

CHARACIFORMES : HEMIODONTIDAE AND PARODONTIDAE

The Hemiodontidae and Parodontidae are morphologically similar in diverse aspects ( Roberts, 1974) and have been grouped together in the subfamily Hemiodontinae by some authors ( Regan, 1911; Eigenmann, 1912; Géry, 1959). Roberts (1974) noted various features common to hemiodontids and parodontids, but noted that evidence of a close relationship between these families was ‘inconclusive’. Langeani (1998) explicitly enumerated several derived features shared by the two families, but considered such shared similarities as parallelisms in light of the phylogenetic hypothesis proposed by Buckup (1998) under which the two families did not resolve as sister taxa. Amongst the more encompassing cladistic analyses of the Characiformes produced to date, only the molecular study of Calcagnotto et al. (2005) proposed the Hemiodontidae and Parodontidae as sister groups. At least one unequivocal and highly distinctive feature of the adductor mandibulae corroborates that hypothesis: [7] the entire rictalis inserting solely onto the maxilla (present study; Datovo & Castro, 2012; note – this subordinal character not shown on Fig. 27). This condition is not found elsewhere either within the Characiformes or amongst most other ostariophysans. Within the lower Teleostei, only gonorynchiforms also exhibit a rictalis inserting solely on the maxilla, but such an occurrence is most parsimoniously interpreted to be convergent with that of hemiodontids and parodontids in light of present concepts of relationships amongst ostariophysans.