alvarezi, Cyprinodon Miller [R. R.] 1976:72, Fig. 1D [Bulletin of the Southern California Academy of Sciences v. 75 (no. 2); ref. 7032] Spring-fed pond at El Potosí, Nuevo León, Mexico, 24°51'N, 100°19'W, elevation 1900 meters. Holotype: UMMZ 179638. Paratypes: ENCB P.890 (27); UMMZ 179639 (314, now 299), 189021 (217, 8 c&s); USNM 217526 (1). •Valid as Cyprinodon alvarezi Miller 1976 -- (Espinosa Pérez et al. 1993:32 [ref. 22290], Lozano-Vilano & Contreras Balderas 1993:307 [ref. 21105], Contreras-Balderas & Lozano-Vilano 1996:34 [ref. 22301], Echelle & Echelle 1998:854 [ref. 23614], Lozano-Vilano & Contreras-Balderas 1999:382 [ref. 23796], Lazara 2001:81 [ref. 25711], Lozano-Vilano 2002:21 [ref. 27832], Nelson et al. 2004:108 [ref. 27807], Miller 2006:296 [ref. 28615], Scharpf 2007:30 [ref. 30398], Page et al. 2013:106 [ref. 32708], Lozano-Vilano & De la Maza-Benignos 2016:15 [ref. 35401], Esmaeili et al. 2018:10 [ref. 36738], Page et al. 2023:141 [ref. 40505]). Current status: Valid as Cyprinodon alvarezi Miller 1976. Cyprinodontidae: Cyprinodontinae. Distribution: Southern North America: El Potosí spring, northwest of Galeana (Veracruz, Mexico) endemic [now extinct in the wild]. Habitat: freshwater.