Revalidation of the genus Ectrepopterus Fowler (Teleostei: Characiformes), with the redescription of its type species, E. uruguayensis

Ectrepopterus uruguayensis Fowler 1943 is redescribed based on the holotype and new series of additional specimens from the rio Uruguay, rio Negro, and small coastal rivers in Uruguay draining to the rio de La Plata. Previously proposed synonyms of Ectrepopterus Fowler 1943 to Megalamphodus Eigenmann 1915 and Hyphessobrycon Durbin 1908 are tested and refuted. A new diagnosis is presented for the genus based on the following apomorphies: foramen in posterior region of metapterygoid forms an incomplete arch, bordered posteriorly by the hyomandibula; pectoral-fin rays bearing hooks; posterior margin of second infraorbital posteroventrally oblique and second infraorbital ventrally bordering anterior region of third infraorbital; fourth infraorbital more developed longitudinally than dorsoventrally; ascending process of premaxilla reaching just anterior end of nasal; and lateral line interrupted.