flavicaudatus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1990:18, Figs. 4-5 [Ichthyological Exploration of Freshwaters v. 1 (no. 1); ref. 14543] Vicinity of Lagoa Grande, County of Santa Maria da Boa Vista, Pernambuco, Brazil, about 9°00'S, 40°20'W, elevation 300 meters. Holotype: MZUSP 40129. Paratypes: MHNM 3252 (1), MNRJ 11556 (1), MZUSP 40130 (1). •Valid as Cynolebias flavicaudus Costa & Brasil 1990 -- (Costa 1995:55 [ref. 22097]). •Valid as Simpsonichthys flavicaudatus (Costa & Brasil 1990) -- (Costa et al. 1996:19 [ref. 22219], Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:297 [ref. 25711], Costa 2003:44 [ref. 26768], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:26 [ref. 28771], Costa 2006:17 [ref. 28620], Costa 2007:108 [ref. 29445], Endruweit 2009:61 [ref. 30288]). •Valid as Hypsolebias flavicaudatus (Costa & Brasil 1990) -- (Costa & Amorim 2011:99 [ref. 31380], Costa 2011:222 [ref. 31654], Costa et al. 2012:72 [ref. 31845], Costa et al. 2012:72, 77 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Loureiro et al. 2018:11 [ref. 36240]). Current status: Valid as Hypsolebias flavicaudatus (Costa & Brasil 1990). Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Pernambuco, northeastern Brazil. Habitat: freshwater.