falcirostris, Hydrocyon Cuvier [G.] 1819:361, Pl. 27 (fig. 2) [Mémoires du Muséum National d'Histoire Naturelle, Paris (N. S.) (Série A) Zoologie v. 5; ref. 1017] Brazil. Holotype (unique): MNHN A-8604 (poor condition). Type catalog: Bertin 1948:7 [ref. 19577]. •Valid as Acestrorhynchus falcirostris (Cuvier 1819) -- (Menezes & Géry 1983:590 [ref. 8307], Ortega & Vari 1986:7 [ref. 9708], Taphorn 1992:99 [ref. 23654], Menezes in Reis et al. 2003:232 [ref. 27061], López-Fernández & Winemiller 2003:204 [ref. 27386], Toledo-Piza 2007:755 [ref. 29426], Barriga Salazar 2014:109 [ref. 35745], Sarmiento et al. 2014:183 [ref. 35004], DoNascimiento et al. 2017:45 [ref. 35633], Careaga et al. 2020:75 [ref. 37774], Silvano et al. 2020:43 [ref. 38133], Meza-Vargas et al. 2021:15 [ref. 39298], Taphorn et al. 2022:10 [ref. 41297], Cortés Hernández et al. 2023:455 [ref. 40760]). Current status: Valid as Acestrorhynchus falcirostris (Cuvier 1819). Acestrorhynchidae: Acestrorhynchinae. Distribution: South America: Amazon and Orinoco River basins and rivers of Guyana (Brazil, Colombia, Bolivia, Ecuador, Guyana, Peru and Venezuela). Habitat: freshwater.