The monophyly of Hypopomus Gill, 1864 is corroborated, on the basis of the presence of mouth corner upturned, homoplastically also in Steatogenys Boulenger, 1898. Its synonymy with Parupygus Hoedeman, 1962 is corroborated. Three of seven synapomorphies attributed to the monophyly of Hypopomidae are refuted (posterior region of parasphenoid narrow, depression on the dorsal surface of bashyal and trapezoidal opercle) and four other are presented to unite Hypopomus to Rhamphichthyidae (lower jaw included; anterior elongation of dentary; elongation of palatine cartilage and ascending process of mesopterygoid backward curved). Thus, further studies are necessary to assess the phylogenetic position of the genus.
Cladistics; Ostariophysi; neotropical region; Parupygus; Steatogenys
