Unio cyrenoides Philippi, 1847
Philippi, 1847. Zeitschr. f. Malakozool. 4(6): 93.
Philippi, 1848. Abbild. Beschr. Conch. 3: 79, pl. 5, fig. 1.
Type(s): HOLOTYPE (MONOTYPY) MNHNS_50199, Lake Nicaragua.

Plagiola (Ptychoderma) cyrenoides — Simpson (1900)
Unio (Arotonaias) cyrenoides — Martens (1900)
Plagiola (Arotonaias) cyrenoides — Simpson (1914)
Arotonaias cyrenoides — Frierson (1927), Graf & Cummings (2007), Bogan (2010), Graf & Cummings (2021), Bieler (2021), Cummings et al. (2025)
Pachynaias cyrenoides — Haas (1929)
— Haas (1969)

Unio newcombianus Lea, 1856
Lea, 1856. Proc. Acad. Nat. Sci. 8: 103.
Lea, 1857. Jour. Acad. Nat. Sci. 3 [O. 6]: 312 [32], pl. 30, fig. 27.
Type(s): LECTOTYPE USNM_84419 (by Cummings et al., 2025: 150), Lake Nicaragua, Nicaragua.

Plagiola (Ptychoderma) cyrenoides — Simpson (1900)
Unio (Arotonaias) newcombianus — Martens (1900)
Plagiola (Arotonaias) cyrenoides — Simpson (1914)
Arotonaias cyrenoides — Frierson (1927), Bieler (2021), Cummings et al. (2025)
— Haas (1969)

Unio sagrinatus Sowerby, 1868
Sowerby, 1868. Conch. Icon. 16: pl. 67, sp. 345; errata [changed to ‘U. newcombianus Lea’].

Plagiola (Ptychoderma) cyrenoides — Simpson (1900)
Unio (Arotonaias) newcombianus — Martens (1900)
Plagiola (Arotonaias) cyrenoides — Simpson (1914)
Arotonaias cyrenoides — Frierson (1927), Cummings et al. (2025)
— Haas (1969)

Unio gabbianus Martens, 1900
‘Lea’ Martens, 1900. Biol. Centr.-Amer., Moll.: pl. 39, figs. 5-5b.
(misidentified reference to Unio gabbianus Lea, 1868)

Plagiola (Arotonaias) cyrenoides — Simpson (1914)
Arotonaias cyrenoides — Frierson (1927)
— Haas (1969)

Unio newcombii Lea, 1868
Lea, 1868. Jour. Acad. Nat. Sci. 6 [O. 12]: 295, errata.
(error for Unio newcombianus Lea, 1856)

Arotonaias cyrenoides — Bieler (2021), Cummings et al. (2025)