Prorivulus Costa.

A monotypic non-annual genus, P. auriferus Costa, Lima & Suzart, from the coastal drainages of northeastern Brazil, is diagnosed by the presence of soft anal fin rays in females, minute urogenital papilla in males, and absence of a dark bar on iris. It has some morphological characteristics similar to Kryptolebias, but other characters more closely align with the rest of Rivulidae . According to the original description it would be the sister taxa of all Rivulidae except Kryptolebias (Costa, 2004b, 2006a). Unfortunately, it has never been included in any subsequent phylogeny or revision, and its position remains uncertain.