A new genus of pimelodid catfishes, Propimelodus, is diagnosed by hypertrophied structures of the palatine and ectopterygoid bones. The type species of Propimelodus is Pimelodus eigenmanni Van der Stigchel (1946). This species belongs to the “Calophysus-Pimelodus clade” and “Pimelodus group” of Lundberg et al. (1991) but within the latter the systematic position of P. eigenmanni remains unresolved.

The name Pimelodus altipinnis Steindachner (1864) is often incorrectly applied to P. eigenmanni. Pimelodus altipinnis belongs in the heptapterid catfish genus Pimelodella. Under earlier editions of the International Code of Zoological Nomenclature, Van der Stigchel's P. eigenmanni was treated as unavailable due to primary homonomy with the earlier Pimelodus eigenmanni Boulenger (1891), a species placed in Pimelodella since Eigenmann (1917). However, the 4th edition of the Code directs use of Van der Stigchel's name because the two species originally named Pimelodus eigenmanni were never concurrently considered to be congeners. Based largely on recently collected material from the eastern Amazon and coastal rivers of French Guiana, Van der Stigchel's P. eigenmanni is redescribed and compared to other members of the “Pimelodus group.”

Genus novum: Propimelodus Lundberg & Parisi.